Mental Math Grade 6 Teacher's Guide

• Break Up and Bridge (Review)
Situations must be regularly provided to ensure
that students have sufficient practice with mental
math strategies and that they use their skills as
required. It is recommended that regular, maybe
daily, practice be provided.
This strategy is similar to front-end addition except that you begin with
all of the first number and then add on parts of the second number
beginning with the largest place value. Students will use the front-end
strategy that makes the most sense to them and is easiest to use.
Examples
a) For 45 + 36, think, “45 and 30 (from the 36) is 75, and 75 plus 6 (the
rest of the 36) is 81.”
b) For 537 + 208, think, “537 and 200 is 737, and 737 plus 8 is 745.”
c) For 5300 plus 2400, think, “5300 and 2000 (from the 2400) is 7300
and 7300 plus 400 (from the rest of 2400) is 7700.”
d) For 3.6 plus 5.3, think, “3.6 and 5 (from the 5.3) is 8.6 and 8.6 plus
0.3 (the rest of 5.3) is 8.9.”
In the initial activities involving a strategy, you
should expect to have students do the
computation the way you modeled it. Later,
however, you may find that some students employ
their own variation of the strategy. If it is logical and
efficient for them, so much the better.
Practice Items
37 + 42 = 72 + 21 = 88 + 16 =
74 + 42 = 325 + 220 = 301 + 435 =
747 + 150 = 142 + 202 = 370 + 327 =
7700 + 1200 = 4100 + 3600 = 5700 + 2200 =
7300 + 1400 = 2800 + 6100 = 3300 + 3400 =
28 Mental Math – Grade 6