Unit 3 – Addition and subtraction
Strategies for mental addition and subtraction
We can use different strategies to help us add. 55 + 43 = 50 + 5 + 40 + 3 = 90 + 8 = 98 What is the same and what is different about each method? Use subtraction to check the calculation. What strategy will you choose? 55 +40 +3 95 98
1 We can use number facts to help solve addition problems. 42 + 43 75 + 29 10 + 90
37
9781380050694__text.indb 37
04/05/2022 15:49
Made with FlippingBook Learn more on our blog