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Masterclass: Take Action Issue 4 - Staffordshire Learning Net

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<strong>Issue</strong> 4<br />

Spring 2012<br />

MaSTerclass<br />

<strong>Take</strong> action!<br />

Early<br />

counting<br />

Case studies:<br />

Mathematics<br />

Specialist Teacher<br />

programme<br />

gets results<br />

Dot to dot:<br />

Developing the skill<br />

of subitising<br />

Join in:<br />

Test your class with<br />

our puzzles page<br />

Maths teachers move<br />

from excellent to outstanding


<strong>Issue</strong> 4, Spring 2012<br />

<strong>Masterclass</strong> – <strong>Take</strong> action<br />

Welcome<br />

As I reflect on the past few years of the MaST<br />

programme, I can’t help but be impressed and<br />

inspired by teachers who have participated. Not<br />

only have they seen an improvement in their<br />

own mathematics teaching, but there is clear<br />

demonstration that their work is making a big<br />

impact across the school. It is clear that these<br />

teachers are bringing their vision and leadership<br />

skills together to improve schools.<br />

So what makes this so successful There is<br />

no doubt in our minds (or in the minds of head<br />

teachers who have seen these benefits), that<br />

commitment from the head teacher, support for<br />

MaSTs attending meetings during school time,<br />

and support and resources to undertake inschool<br />

activities linked to a school improvement<br />

plan, are key factors. Despite changes<br />

in funding, registration to the programme<br />

continues to rise. The fact that head teachers<br />

are willing to pay this and support their teachers<br />

on the programme (even allowing them to be<br />

away from their classrooms for short periods of<br />

time), shows their very real commitment to the<br />

programme, and their conviction that there will<br />

be a good return on their investment. Each and<br />

every one of those head teachers who has a<br />

member of staff signed up to MaST is giving a<br />

massive vote of confidence to both the MaST<br />

team here at Edge Hill University and to our<br />

local authority partners.<br />

We are now actively recruiting for Cohort 4.<br />

Once again, schools will have the opportunity to<br />

invest in outstanding professional development<br />

which is linked directly to school improvement<br />

plans and which has been demonstrated<br />

to make a huge difference to teaching and<br />

learning, leadership development and<br />

children’s achievement.<br />

If this is the first time you have seen a<br />

MaSTerclass magazine, I extend a very warm<br />

welcome. In this issue we focus on early<br />

counting, with views from two experts in the<br />

field and case studies of MaST in action. Do<br />

get in touch with us if you have comments or<br />

questions. You are a vital part of the three way<br />

partnership – Edge Hill, local authorities and<br />

schools – that is making MaST so successful.<br />

One last word. You may have noticed that<br />

we are using the NCETM logo, indicating<br />

that we, the Edge Hill MaST team, have met<br />

their standard for Continuing Professional<br />

Development provision. This is another<br />

valuable endorsement of the MaST<br />

programme at Edge Hill.<br />

Dr Mary McAteer<br />

MaST Project Director<br />

Edge Hill University<br />

A unique<br />

view of maths<br />

improvement<br />

Senior lecturer Sue Bailey has a unique view of the MaST programme. She<br />

is seconded to the programme at Edge Hill for three days a week, but is still<br />

also a primary maths consultant for Lancashire, which means she gets to see<br />

things from both sides of the fence.<br />

Sue takes an active role in advising teachers currently on the MaST programme, in<br />

supporting them with their assignments, developing teaching material and helping to<br />

organise the Saturday lectures and workshops.<br />

She says: “Having both roles is interesting and gives me a complete picture of the<br />

MaST programme and the impact it is having on mathematics teaching and practice.<br />

I find my involvement in the local meetings particularly useful. I’m there with my<br />

Lancashire hat on; but can take the teachers’ ideas and feed them back into the<br />

central MaST team, and I can see how my local teachers are building up their<br />

subject knowledge.<br />

The two things complement each other. The local meetings are all about cohort<br />

members sharing ideas and knowledge, but then at the workshops and study<br />

days I see them unpicking the deeper theories and rethinking aspects of their own<br />

mathematics teaching.<br />

It is really good, getting to know the students in my local group and seeing them<br />

develop. One particularly encouraging thing is that one group now coming to the end<br />

of its formal local network meetings plans to carry on. The teachers are hoping to<br />

keep meeting up – and that must mean that they find the whole process valuable.”<br />

Having two distinct roles means spinning lots of plates sometimes, but Sue says she<br />

enjoys the constant challenge.<br />

“I really like the student support aspect on MaST, answering questions and making<br />

the whole process clearer for them. I get a lot out of the one-to-one email support<br />

too, and I also enjoy the visiting lecturers and workshops. Getting to know individual<br />

teachers on the programme is really great.<br />

Obviously, there are cost implications when it comes to joining MaST, but I think<br />

most schools see it as an investment in the whole team, not just one member<br />

of staff.<br />

From the teachers’ point of view, it does call for a high level of commitment – there is<br />

work to be done outside of school hours, and it can be challenging – but feedback to<br />

MaST and the positive impact it can have in the classroom has been really good.”<br />

Sue Bailey<br />

Calling all new recruits<br />

to MaST<br />

We are now recruiting for a new MaST cohort, so why not sign up for a unique<br />

programme of professional development leading to lasting school improvement<br />

It’s a win-win. One teacher<br />

takes part in MaST, but<br />

every member of a school’s<br />

teaching staff can benefit<br />

from the programme because<br />

as they grow into their role,<br />

a Mathematic Specialist<br />

Teacher works closely with<br />

colleagues to identify needs<br />

and support professional<br />

development opportunities<br />

in mathematics.<br />

Jan Jackson<br />

Schools taking part in MaST<br />

get a new tool for lasting<br />

classroom improvement as<br />

well as a positive impact on the quality of teaching and learning<br />

in school and a reinvigorated attitude towards maths for teachers,<br />

children and parents.<br />

Numbers are increasing with each Edge Hill MaST cohort, as<br />

head teachers begin to see the wider benefits of the programme,<br />

and feedback clearly shows that MaST can lead to improvements<br />

in pupil attainment .<br />

Teachers who successfully complete the MaST programme<br />

are awarded a Postgraduate Certificate in Specialist Primary<br />

Mathematics (worth 60 credits at Masters Level) and Mathematics<br />

Specialist Teacher status.<br />

Case study<br />

MaST has transformed<br />

my career<br />

The MaST programme not only<br />

boosted Rachel Burns’ confidence –<br />

it also transformed her teaching day.<br />

Rachel is now teaching mathematics full time at Moor Green<br />

Primary School in Birmingham; something she says could<br />

never have happened without MaST.<br />

She says: “I have got my dream job. I have gone from being a<br />

classic maths phobic to a fully fledged maths geek – and proud<br />

of it. Seriously, the programme made me much more aware of<br />

the massive range of resources on offer and put me in touch<br />

with a group of people who have taught me so much. The<br />

interaction with other teachers on the programme was really<br />

important and helped give me good ideas.<br />

I have been able to transfer the learning straight into the<br />

classroom. I have now taught maths to every year group,<br />

Sounds like a great opportunity It is – but it also calls for<br />

commitment, with some events and personal study at weekends<br />

and ‘out of hours’.<br />

Jan Jackson, MaST Project Manager says: “MaST is evolving<br />

from an excellent professional development and school<br />

improvement programme into an outstanding one.<br />

When I speak to teachers taking part it is quite clear that their<br />

view of mathematics changes – and so does the methods they<br />

use. MaST gives them the benefit of expert opinion and new<br />

thinking, and an opportunity to hear from fellow teachers in<br />

other settings. This sharing of knowledge is fundamental to<br />

the programme’s success.<br />

MaST isn’t something you devote the occasional hour to; it tends<br />

to become all consuming, which is great, because that can only<br />

be down to the enthusiasm and vigour of the teachers involved.”<br />

Remember:<br />

This is your last chance to get partial funding from DfE<br />

(they pay half of the first year).<br />

It’s great value for money – the whole school benefits, and<br />

MaST provides 12 half days of Local Consultant time, plus<br />

keynote speakers who are leaders in the field. To find out<br />

more call 01695 650774 or email mast@edgehill.ac.uk.<br />

even Reception, and am also working with small groups of<br />

gifted and talented pupils.<br />

I have also contributed to a maths training day for NQTs run<br />

by the local authority maths adviser. I would not have had<br />

the confidence to do something like that before. Maths was<br />

a subject I did not enjoy at school and I would never have<br />

believed I could end up doing this.<br />

MaST has given me a deeper subject knowledge and<br />

pedagogy and real enthusiasm for the subject which has<br />

been transferred to the children. We run a maths club at<br />

school, and the children are so keen to learn.<br />

I think the programme was excellent; probably the best<br />

professional development I have come across. I was one<br />

of the first to take part and it’s no exaggeration to say<br />

that MaST has transformed my outlook, my teaching<br />

and my career.”<br />

2<br />

jacksonj@edgehill.ac.uk<br />

jacksonj@edgehill.ac.uk<br />

3


<strong>Issue</strong> 4, Spring 2012<br />

<strong>Masterclass</strong> – <strong>Take</strong> action<br />

Look and learn:<br />

join the<br />

subitising set<br />

When you play a board game using dice you are probably subitising. It’s the<br />

same with dominoes. As any mathematics teacher will know, subitising is the<br />

ability to recognise the number of objects (dots, in the example of dice) without<br />

actually counting them.<br />

Ian Sugarman<br />

This method of knowing a number simply by looking at a grouping<br />

is something most adults take for granted, but it is a skill that is<br />

developed at a very young age.<br />

Pre-school children can quickly learn to recognise small groups<br />

of dots, or lines (or just about any object) without having to count<br />

them individually, and their ability to do this is a fundamental<br />

building block in the teaching of number to Reception and Year<br />

One pupils.<br />

Primary Mathematics Consultant Ian Sugarman is a visiting<br />

lecturer on the Edge Hill University MaST programme and has<br />

focused on this subitising skill, helping teachers to see the<br />

benefits of actively developing it in their pupils and showing<br />

how it can lead to a better understanding of number and early<br />

strategies of calculating.<br />

Ian explains: “Often in the teaching of four and five year olds the<br />

emphasis is on mechanically counting small quantities of things.<br />

But children can ‘see’ these numbers as a group from an early<br />

age, and if a teacher can draw a child’s attention to his or her<br />

ability to visualise numbers in this way, it helps give the child a<br />

deeper understanding of how numbers relate to each other and<br />

it can have a big impact when children move on to calculating<br />

numbers mentally.”<br />

Benefit<br />

“By encouraging subitising a teacher is getting a child to use<br />

both sides of the brain: it is not just about memory or mechanical<br />

counting; it is about recognising shapes and patterns, which is a<br />

different skill and of huge benefit in early number work.<br />

Often children can see groupings very quickly, and this is<br />

something Ian demonstrates by quickly flashing an image onto a<br />

screen and asking children to reproduce it. Some children may<br />

need to look up two or three times, but most can hold the image<br />

in their mind and reproduce it perfectly after seeing it fleetingly<br />

for just a couple of seconds.<br />

He explains: “You put a simple line drawing on the screen and<br />

ask the children to copy it using a pile of sticks on a table in front<br />

of them. If there is a pattern or a symmetrical element to the shape,<br />

children can hold onto that image and reproduce it easily. Crucially,<br />

they know how many sticks are needed to recreate the shape.<br />

I encourage teachers on MaST to introduce this sort of activity into<br />

the classroom. It is fun of course, but it develops and enhances<br />

this subitising skill, which is a way of getting children to slow<br />

down and explore numbers, examining them in a way that simple<br />

mechanical counting does not.”<br />

Skills<br />

The ability to see groups instead of counting separate items leads<br />

to other important skills when children move onto more complex<br />

number work. For example, if a child can see a group of sticks,<br />

and identify how many triangles could be made from those sticks,<br />

they can also see how many ‘threes’ they need.<br />

Ian says: “There are lots of ways to engage children. It used to<br />

be a case of using flash cards, which were then replaced by a<br />

series of Powerpoint slides. But now I’ve been able to offer this<br />

as a ready-made software activity. It’s the sort of activity that<br />

should be done little and often in the classroom because it is not<br />

a maths technique that can be compartmentalised – it flows into<br />

many aspects of number work.<br />

I had one teacher in a previous lecture who told me that these<br />

ideas on subitising had completely transformed the way she and<br />

her colleagues approached counting with Early Years pupils.<br />

At her setting they had reorganised and given a fresh priority to<br />

this skill, and I don’t think that’s unusual.<br />

Adults can forget that their ability to ‘see’ groups of things without<br />

counting is a skill that underpins their understanding. Getting<br />

back to basics and building these activities into lessons for the<br />

youngest learners can have a big impact.”<br />

More about Ian…<br />

Ian Sugarman has many years experience as a Primary<br />

practitioner, advisory teacher in Shropshire and trainer of<br />

Primary teachers at Manchester Metropolitan University.<br />

He has produced an extensive range of mathematics<br />

curriculum materials, served on QCA committees producing<br />

guidance on the teaching of mental and written calculation<br />

strategies and the writing and reviewing of SATs.<br />

He is a well established author of journal articles and<br />

curriculum booklets and has served on UK Government<br />

committees for the production of national assessment<br />

packs and guidance. With 25 years experience as a<br />

training provider for Primary teachers he is still very much<br />

classroom-based, and since retiring from MMU has been<br />

working with both gifted and talented and under-attaining<br />

pupils at several schools.<br />

He is co-author of Numbergym software, designed for<br />

non-specialist teachers and parents from Foundation<br />

stage to GCSE.<br />

For more information and ideas see his website at<br />

www.sugarmaths.net<br />

Case study<br />

Putting Ian’s<br />

ideas into<br />

action<br />

Ian Sugarman’s lecture on subitising<br />

led to a change of practice in the<br />

Reception class at Aspull Church<br />

Primary School near Wigan.<br />

Teacher Alison Moore was a member of the first MaST<br />

cohort and says that introducing some of Ian’s techniques<br />

for number recognition has made a big difference to pupils.<br />

She says: “I had gone from being a Year 6 teacher to<br />

Reception, and of course the younger children had very<br />

different needs when it came to learning maths.<br />

After hearing Ian’s lecture I decided to try out some of the<br />

ideas and the children did really well as a result. We used<br />

dice games and looked at patterns and somehow it just<br />

‘clicked’ with them – it made a tangible difference.”<br />

Training<br />

“I have been able to incorporate other elements of the<br />

MaST programme into our teaching, and we are just starting<br />

to include some things into staff training too, which means<br />

my colleagues also get the benefit of the learning.<br />

MaST enables you to look more closely at how young<br />

children learn maths and helps you to deal with some of<br />

the most common problems they can face.<br />

The local meetings on the programme were very useful<br />

as a way of sharing ideas, and getting together with other<br />

teachers helps you see that the same ‘problems’ in teaching<br />

and learning maths occur at many other schools.<br />

My colleagues on the cohort were a very important source<br />

of support, and even though I finished the programme at<br />

Christmas, I still keep in touch with them.<br />

Being part of the first MaST cohort meant that I wasn’t<br />

exactly sure what to expect. Although it’s true that MaST<br />

demands considerable personal commitment and<br />

can be time consuming when you already have a<br />

full time job, I would recommend it to others.”<br />

4<br />

jacksonj@edgehill.ac.uk<br />

jacksonj@edgehill.ac.uk<br />

5


<strong>Issue</strong> 4, Spring 2012<br />

<strong>Masterclass</strong> – <strong>Take</strong> action<br />

One, two, three steps<br />

to success in<br />

early counting<br />

Early number expert Professor Effie MacLellan, Research Professor of Education<br />

at the University of Strathclyde, is a visiting lecturer on the MaST programme. A<br />

former primary school teacher, she advocates the use of simple classroom-based<br />

counting techniques to help young children understand both the concept and its<br />

importance. Here she answers some questions frequently asked by teachers.<br />

She says: “What does it mean to say<br />

that someone can count For adults,<br />

counting is a seemingly straightforward<br />

activity: they notice the set of items to<br />

be counted, assign a number name to<br />

each item and recognise that the last<br />

number name used defines the total<br />

number of items in the set.<br />

That adults are skilled in counting<br />

is not surprising – most of us have<br />

Effie MacLellan been practising since the age of<br />

two. Of course two year olds cannot<br />

count with the same level of skill as<br />

adults, but research shows that the rudiments of counting can be<br />

observed in many two year olds. Counting is both a very complex<br />

process and a very important process.”<br />

How long does it take for a child to<br />

learn the number names<br />

How long is a piece of string Most children will have learned the<br />

sequence up to 100 by about six or seven years of age. Typically,<br />

two to three year olds can reliably produce the string ‘one, two,<br />

three’, though after ‘three’ may become confused. The hardest<br />

part of learning the number names is learning the sequence from<br />

‘one’ to ‘thirteen’, because all the names are so very different from<br />

each other. By the time the child has learned the number name<br />

sequence to ‘twenty’, they may have spotted part of the repeating<br />

one to nine pattern: four and fourteen, six and sixteen and so<br />

on. Once children have mastered the number name sequence to<br />

twenty and have grasped the repeating pattern, all that is left is for<br />

them to learn the decade names: thirty, forty, and so on. It takes<br />

most young children four or five years to learn the number name<br />

sequence up to one hundred.<br />

Can children count when they know<br />

the number names<br />

Categorically no. Counting involves much more than the rehearsal<br />

of strings of number names. Counting involves three procedures.<br />

First, there has to be a pairing of each item with a number name.<br />

Someone counting has to mentally ‘move’ (and possibly physically<br />

move) each item from a to-be-counted category to an alreadycounted<br />

category and, at the same time, must assign a different<br />

number name to each item. This pairing is open to error. One is<br />

when the person counting either counts an item twice or misses<br />

one out. Another error is when there is a mistake made in using<br />

the number names (perhaps using the same number name twice).<br />

A third is when the person counting fails to ‘move’ and name the<br />

items in a synchronised fashion: for example the number naming<br />

may be in advance of the ‘moving’ of items; the naming may<br />

continue after the ‘moving’ is complete; or during the procedure<br />

there may be a failure to maintain one-to-one correspondence so<br />

that although the procedure begins and ends in synchrony, there<br />

has been some confusion in between.<br />

Second, while assigning a number name once, and only once, to<br />

each item in the array is important, it is not enough. Additionally,<br />

the sequence of number names generated must be reliably<br />

produced from one count to another. We have to learn a stable<br />

list of counting words and use this list consistently.<br />

The third procedure is the recognition that the final number name<br />

used has a special significance. This final number name defines<br />

the total number of items which were counted. This is later in<br />

developing than the first two procedures and is dependent upon<br />

the first two. A child may be able to pair number names and<br />

items-to-be-counted and may assign the number names in a<br />

fixed order but may not further know that the last number name<br />

assigned represents the numerosity of the items.<br />

I was taught that before children can<br />

really learn to count, they must be able<br />

to sort objects into groups<br />

Yes, but this is only a bit of the story. Actually children will count<br />

elephants, bananas and toys or girls and lollipops and refer<br />

to such collections as “things”. This means that the ‘sorting’<br />

activities, often used in early education, are not as important<br />

to understanding counting as was once thought.<br />

So if ‘sorting’ activities are not essential,<br />

what about ‘matching’ Don’t children<br />

need one-to-one correspondence before<br />

they can count<br />

Yes, children do need one-to-one correspondence in order to<br />

count, but what is questionable is whether children need to<br />

engage in the ‘matching’ activities of assigning straws to cups of<br />

juice or eggs to egg cups. If the child can pair a number name with<br />

an item and continue pairing a different number name to each new<br />

item in the set, the child already has one-to-one correspondence.<br />

Remember that one-to-one correspondence is an abstract notion;<br />

it is not something we can see.<br />

Is counting important<br />

Yes. Counting is a pre-requisite for many other mathematical<br />

activities such as telling the time and multiplying. And counting<br />

is the means by which young children penetrate the concepts<br />

of addition and subtraction. When a set of items has been<br />

transformed either through some items being<br />

added or removed, the only strategy which the<br />

young child has for defining the outcome of the<br />

transformation is counting. When children<br />

start school, they may have informal knowledge<br />

of addition and subtraction.<br />

Case study<br />

Looking at practice<br />

in the Pacific<br />

Big changes could be on the cards<br />

for Katie Hebden, a Year 3 teacher<br />

from Millfields CE Primary on the<br />

Wirral. She is hoping that involvement<br />

in MaST will help her secure a<br />

teaching role in New Zealand.<br />

She says: “I think the programme is really good at developing<br />

your understanding of the child as a mathematical learner.<br />

You would not get that in everyday teaching.<br />

I teach Year 3, but since MaST have been doing some<br />

intervention work with small groups and also some one-to-one,<br />

helping children overcome their maths misconceptions.<br />

The programme was very useful. I now know where to<br />

find good resources and the pedagogy was excellent.<br />

It was certainly more than just an investment in me;<br />

What can I do to promote the young<br />

child’s counting<br />

Good readers are the people who do a lot of reading; young<br />

children who are good at counting tend to have done lots of<br />

counting. Many children count when there is nothing in the<br />

immediate environment which demands it: they get intrinsic<br />

satisfaction from counting.<br />

• For children who have not developed the conventional list of<br />

number words, there is nothing to be lost by some rote counting:<br />

rehearsing the sequence of number names, perhaps to ten.<br />

• The pairing of a number name with an item can be better<br />

managed by children if they point to each item in the set.<br />

Pointing, while saying the number names, is a cue to the<br />

child that each item is counted once and only once.<br />

• Be ready to show the children the observable behaviour you<br />

wish them to demonstrate. If you want the children to touch<br />

the items as they are being counted, show them clearly what<br />

you want. Check and correct, with further demonstration, those<br />

who are having problems in synchronising the touching and<br />

the naming. Similarly, be ready to make explicit what children<br />

seem to know, but do not articulate clearly. For example, having<br />

executed a count correctly, the children can be reminded that<br />

the last number name used tells how many are in the set.<br />

• Don’t worry if children use their fingers to make sense of<br />

counting more easily. Traditionally there has been a fear that<br />

children would become over dependent by a reliance on<br />

fingers for counting but there is no evidence to suggest that<br />

by using their fingers to support their counting, children are<br />

handicapping themselves, either short or long term.<br />

it is about sharing the ideas and activities with other teachers<br />

and TAs in my school.<br />

Whilst researching for my initial assignment on language<br />

within mathematics I was interested in how this was widely<br />

developed and focused on in the Pacific region, especially<br />

New Zealand education. It appeared that the children<br />

progressed a lot quicker at an earlier stage with only the<br />

key concepts being taught.<br />

When it was time to do my second assignment I looked again<br />

at their Maths Curriculum and really liked the emphasis they<br />

gave to their teachers’ pedagogy and wanted to be part of it.<br />

So at Easter I am travelling to New Zealand where I hope to<br />

gain a teaching position, and after speaking to a few Head<br />

Teachers already it seems that a Primary maths specialist is<br />

something they are very interested in having.<br />

I would recommend MaST; but it does represent a lot of work<br />

and so demands a big personal commitment. I would say that,<br />

having now completed MaST, I feel one step ahead.”<br />

6<br />

jacksonj@edgehill.ac.uk<br />

jacksonj@edgehill.ac.uk<br />

7


The classic ‘6801<br />

to 1089 trick’<br />

Dr Mark<br />

Effect:<br />

You predict the 4-digit number<br />

your victim will calculate from<br />

a 3-digit number they choose<br />

What<br />

you<br />

need:<br />

A victim... er... I mean volunteer<br />

A pencil (or pen) and paper for writing down calculations<br />

Maybe a calculator to help with the calculations<br />

A blank sheet of paper<br />

L<br />

What L<br />

to do:<br />

Without letting anyone see what you are writing,<br />

write the number ‘680I’ on a blank sheet of paper.<br />

<br />

NOTE: Make sure you write the number ‘one’ at the end using just<br />

a single vertical line, and don’t insert a comma between the ‘6’<br />

and ‘8’ as some people do – you’ll see why later!<br />

Choose your victim... er... volunteer and ask them to carry out the<br />

following instructions:<br />

1. Think of any 3-digit number and write it down, making<br />

sure that the first and last digits of your 3-digit number<br />

are different, or, perhaps a simpler instruction, just<br />

choose a 3-digit number without any repeated digits.<br />

This is your FIRST 3-digit number.<br />

- Worked example: Your volunteer might choose their FIRST<br />

number as ‘123’.<br />

2. Now write down a SECOND 3-digit number, whose digits<br />

are the exact reverse of your FIRST 3-digit number.<br />

- Worked example: If their FIRST number is ‘123’, then their<br />

SECOND number will be ‘321’.<br />

3. Using a calculator if you like, now subtract the smaller<br />

3-digit number from the larger 3-digit number, to<br />

produce a THIRD 3-digit number. Note that if you<br />

should end up with a 2-digit answer number, then<br />

you should simply insert a ‘0’ in front of it to make it a<br />

3-digit number that now starts with the digit ‘0’ in the<br />

hundreds column.<br />

For example, suppose your volunteer had instead chosen their<br />

first 3-digit number as ‘201’; then their second 3-digit number<br />

would have been ‘102’. Subtracting ‘102’ from ‘201’ produces<br />

the 2-digit answer ‘99’. To make this a 3-digit number they<br />

would simply insert a ‘0’ in front of the ‘99’ to make the 3-digit<br />

number ‘099’.<br />

- Worked example: Subtracting ‘123’ from ‘321’ equals ‘198’<br />

(THIRD 3-digit number).<br />

4. Now write down a FOURTH 3-digit number, whose digits<br />

are the exact reverse of your THIRD 3-digit number.<br />

- Worked example: Their THIRD number is ‘198’, so their<br />

FOURTH number will be ‘891’.<br />

5. Finally, ADD together your THIRD and FOURTH 3-digit<br />

numbers to get a final 4-digit number answer, and write<br />

it down.<br />

- Worked example: Adding ‘198’ to ‘891’ equals ‘1089’<br />

Now reveal your sheet of paper to your volunteer with the<br />

number ‘680I’ you wrote on it earlier, and say:<br />

“This is your final 4-digit number!”<br />

Your volunteer will now no doubt sneer that you are<br />

TOTALLY WRONG!<br />

Look a little downcast and confused, pause for thought and then<br />

look at your sheet of paper with the number ‘680I’ written on it, and<br />

say, “A-ha! I see what I’ve done wrong.” Then simply turn your<br />

sheet of paper around upside-down, where the original ‘680I’ now<br />

reads as ‘I089’ – your volunteer’s final 4-digit number!<br />

<strong>Take</strong> a bow!<br />

What’s going on:<br />

This is a ‘classic’ number trick and usually amazes those who have not come across it before and can still confuse even those who have!<br />

As you’ve no doubt realised by now, it works with any 3-digit number at the start, provided the first and last digits are different. This trick is a<br />

good source for problem solving, reasoning and further investigation, not least by repeating the trick with different starting 3-digit numbers,<br />

which will give further practice with adding and subtracting, paper arithmetic, place value and calculator work.<br />

For another ‘magical’ version of this trick, along with a detailed mathematical explanation of how it actually works – including the algebra<br />

(ARRRRGH!) – enter the following URL into your favourite browser: www.dr-mark.co.uk/monthlyMaths/monthlyMathsJan2012.pdf<br />

For details of Dr Mark’s range of science and maths in-school pupil shows, in-school teachers’ CPD, his teachers’ resources books,<br />

CDROMs and DVDs, and FREE RESOURCES NEWSLETTER, visit his website at: www.dr-mark.co.uk<br />

© Dr Mark Biddiss 2012. Dr Mark’s INSPIREducation: INSPIREmathsTM Web: www.Dr-Mark.co.uk<br />

We are happy to share, but please ask before reproducing stories and photographs<br />

from MaSTerclass magazine. Contact: jacksonj@edgehill.ac.uk<br />

© Edge Hill University 2012. The publisher, authors and printers cannot accept<br />

liability for errors or omissions. Designed and produced by Epigram 0161 237 9660

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