Addition and Subtraction Math Strategies

Here are the new addition/subtraction strategies that we are learning in class. If you get confused or need a reminder check out the examples below!

Addition Strategies

1) Add the tens, then add the ones.
68+27=?
68+20=88
88+7=95
So, 68+27=95

2) Add the nearest ten, then subtract the extra ones.
44+38=?
44+40=84
84-2=82
So, 44+38= 82

3) Add 100 (round 2nd # to 100), then subtract the extra ones.
65+97=?
65+100= 165
165-3= 162
So, 65+97=162

4) Add the 100’s (round both #’s to 100), then subtract the extra ones.
96+95=?
100+100=200
200-4-5= 191
So, 96+95=191

Subtraction Strategies
1) Subtract the tens, then subtract the ones.
67-43=?
67-40= 27
27-3=24
So, 67-43= 24

2) Round to the nearest ten, then subtract the tens. Last, add the extra ones.
35-29=?
35-30= 5
5+1= 6
So, 35-29= 6