Page 15 - Whole Numbers (Addition and Subtraction)

7. Make a rough drawing of a number line to show how 160 − 70
can be calculated by adding on to 70 as shown on the previous
page.

8. Make a rough drawing of a number line to show how 130 − 80
can be calculated by subtracting 80 piece by piece.
9. Use arrows as you did before to show how the following can be
calculated by filling up to 100.

(a) 120 − 70 (b) 140 − 50
(c) 160 − 70 (d) 130 − 50
10. Show how the following can be calculated by subtracting
piece by piece.
(a) 120 − 80 (b) 140 − 70
(c) 150 − 80 (d) 130 − 80

11. Check each of your answers for questions 9 and 10 by doing
addition.

12. Write the answers for the questions that you can do quickly,
and show with addition that your answers are right. Copy
the number sentences for which you cannot find the answers
quickly.

(a) 100 − 70 = . . . (b) 170 − 80 = . . . (c) 170 − 90 = . . .

(d) 130 − 90 = . . . (e) 170 − 70 = . . . (f) 170 − 60 = . . .

(g) 170 − 10 = . . . (h) 130 − 60 = . . . (i) 160 − 50 = . . .
(j) 100 − 40 = . . . (k) 140 − 80 = . . . (l) 140 − 70 = . . .

(m) 140 − 90 = . . . (n) 140 − 40 = . . . (o) 140 − 60 = . . .

(p) 100 − 90 = . . . (q) 190 − 80 = . . . (r) 190 − 70 = . . .

(s) 100 − 60 = . . . (t) 160 − 80 = . . . (u) 160 − 70 = . . .

(v) 160 − 90 = . . . (w) 160 − 60 = (x) 150 − 70 = . . .

13. Now complete the sentences you have copied in question 12.
You may work in any way you prefer.

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