RIC-0563 Developing algebraic thinking
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
PLUS AND TIMES<br />
Teachers notes<br />
Introduction<br />
Looking at<br />
the algebra<br />
Plus 5<br />
Two operation signs, + and x, provide three easy number tile activities<br />
that give an introduction to <strong>Developing</strong> <strong>algebraic</strong> <strong>thinking</strong>. Number sense<br />
is important. As students begin to look for patterns in various solutions,<br />
a need for algebra becomes clear in order to analyse each activity.<br />
In Plus 5, numerous solutions exist. If we label the 5 digits as shown in<br />
the diagram below, then we have the equation b + a + c = d + a + e<br />
d<br />
b<br />
a<br />
c<br />
e<br />
Simplifying, we obtain the equation b + c = d + e. In other words, the<br />
algebra shows that we only need to find two pairs of number tiles that<br />
have the same sum. The number tile a can be any digit 0 to 9.<br />
The least possible sum occurs when a = 0.<br />
The smallest possible sum satisfying the equation<br />
b + c = d + e is 5 = 1 + 4 = 2 + 3.<br />
The greatest possible sum occurs when a = 9.<br />
That sum is 22 and it occurs when b + c = d + e = 13.<br />
So 13 = 5 + 8 = 6 + 7.<br />
76 DEVELOPING ALGEBRAIC THINKING www.ricgroup.com.au R.I.C. Publications ®<br />
ISBN 978-1-74126-088-5
Change language