Unit 3 – Addition and subtraction
1 Copy and complete. What method will you use each time? Remember to make and estimate first and check your answers. (a) 856 − 423 (b) 685 − 359 (c) 773 − 254 (d) 500 − 230 (e) 956 − 523 (f) 985 − 659 (g) 673 − 154 (h) 800 − 530 What do you notice? Discuss why this has happened. 2 The mass of a cabbage is 852 g. The mass of an onion is 418 g lighter. What is the mass of the onion?
Look at Winston’s subtraction. Explain the mistake he has made. What do you need to tell Winston about subtracting?
3
H 8 3 5
T 5 1 4
O 3 8 5
–
E
Use all the digit cards each time to make different subtractions.
H T O
H T O
−
How many answers can you find that are greater than 250 but less than 450?
45
9781380050694__text.indb 45
04/05/2022 15:49
Made with FlippingBook Learn more on our blog