1 Use the inverse to check these calculations. (a) 85 − 52 = 32 is because
+
=
.
(b) 35 + 43 = 78 is
because
−
=
.
What is the missing number?
2
60
= 95
60 +
95
We can use the inverse to help us. It is easier to use the subtraction − = than 95 − = 60. The missing number is .
1 Write two addition sentences and two subtraction sentences each time. (a) 150 50 200 (b) 5 15 20 2 Use the inverse to check these calculations. Correct any that are wrong. Write down the inverse calculations you use each time.
(a) 72 + 19 = 93 (d) 100 − 47 = 52
(b) 42 − 25 = 17 (e) 32 + 39 = 71
(c) 32 + 43 = 75 (f) 90 − 45 = 55
Find the missing numbers. (a) − 200 = 95 (b)
3
+ 65 = 80
(c) 68 −
= 34
36
9781380050694__text.indb 36
04/05/2022 15:49
Made with FlippingBook Learn more on our blog