UNIT 05 // SESSION B // MASTER WHEN READY

Written subtraction, and the check

Name:Date:

Every answer gets checked by adding back. If it does not come back to the top number, find the mistake.

1Work it out, then check.

52
− 27
check: ___ + 27 =
63
− 48
check: ___ + 48 =
81
− 36
check: ___ + 36 =
74
− 29
check: ___ + 29 =
90
− 53
check: ___ + 53 =
65
− 18
check: ___ + 18 =
43
− 27
check: ___ + 27 =
92
− 45
check: ___ + 45 =

2Someone made a mistake. Find it and fix it.

They wrote: 52 minus 27 = 35. What did they do wrong?

3Word problems. Box first.

aThere were 52 dates in the bowl. The family ate 27. How many are left?
bAva has 81 stickers. Nora has 36. How many more does Ava have?
Question 2The classic error: taking the small digit from the big one in each column regardless of order, so 7 minus 2 gives 5. If she cannot spot it, do it with sticks together.
1. 25, 15, 45, 45, 37, 47, 16, 47   2. They did 7 minus 2 instead of trading. Correct answer 25.   3. a 25, b 45