Page 46 - Whole Numbers (Addition and Subtraction)

4.2 Practise addition and subtraction

1. First estimate the answers to the nearest thousand.
Then calculate the answers.
(a) 3 467 + 5 231 (b) 4 736 + 3 263
(c) 4 891 + 4 119 (d) 3 714 + 6 156
(e) 9 653 − 7 643 (f) 6 487 − 3 397

(g) 8 345 − 7 558 (h) 5 352 − 1 963

2. First estimate the answers to the nearest thousand.
Then calculate the answers.
(a) 765 + 427 + 388 + 628 + 794

(b) 626 + 792 + 425 + 763 + 386

3. Is your answer for question 2(a) ten more than your answer for
question 2(b)?
If the difference between the answers is not ten, you have
made a mistake somewhere.
In this case, go back to your work in question 2, find your
mistakes, and correct your work.

4. Is the calculation below correct or are there mistakes?

2 376 = 2 000 + 300 + 70 + 6

5 669 = 5 000 + 600 + 80 + 9
2 376 + 5 669 = 7 000 + 900 + 150 + 15

= 7 035

Describe any mistakes you find, and then do the calculation
correctly.

5. Check your answers for questions 1(e), (f), (g) and (h) by doing
addition. If some of your answers are wrong, go back to your
work, find your mistakes and correct them.

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