Have 200 Charts readily available.
Ask students to solve each problem
two different ways. Make sure that
mental math strategies are
discussed. One possible strategy for
each is given.
110; break the numbers into
parts and then add
40 + 60 + 4 + 6 = 100 +
10 = 110.
51; I was thinking 100 − 50 =
50 and 101 is one more than
100, so the answer is 51.
98; 184 − 84 = 100 and I
need to subtract 2 more.
200; I thought 175 + 25 which
adds 2 to the first addend and
takes 2 off the second one, so
everything stays the same,
and 175 + 25 = 200.
I. More Than One Way
Solve each problem two different ways. Think about making tens.