Page 7 - Whole Numbers (Addition and Subtraction)

10. Copy the number sentences for which you cannot find the
answers quickly.

(a) 10 + 7 = . . . (b) 7 + 8 = . . . (c) 7 + 9 = . . .
(d) 9 + 7 = . . . (e) 7 + 7 = . . . (f) 7 + 6 = . . .
(g) 7 + 10 = . . . (h) 7 + 4 = . . . (i) 7 + 3 = . . .
(j) 10 + 9 = . . . (k) 9 + 8 = . . . (l) 9 + 2 = . . .
(m) 9 + 10 = . . . (n) 9 + 4 = . . . (o) 9 + 3 = . . .

(p) 10 + 6 = . . . (q) 6 + 8 = . . . (r) 6 + 7 = . . .
(s) 6 + 9 = . . . (t) 6 + 6 = . . . (u) 6 + 5 = . . .
(v) 6 + 10 = . . . (w) 6 + 4 = . . . (x) 6 + 3 = . . .

11. Now complete the sentences you have copied in question 10.
You may work from the facts that you know, or fill up to 10, or
work in any other way you prefer.

3.3 Differences between numbers

The red candle below is 19 units long and the purple candle is
14 units long.

The difference between the lengths is 5 units, or
19 − 14 = 5

1. A certain tree is 16 m tall, and another
tree is 9 m tall. What is the difference
between the heights of the two trees?

2. Calculate each of the following.
(a) 16 − 9 (b) 9 + 7
(c) 8 + 9 (d) 17 − 8
(e) 17 − 9 (f) 6 + 9
(g) 15 − 9 (h) 15 − 6
3. The blue line is 7 cm long, and the red line is 12 cm long.

By how much do the lengths of the two lines differ?

6