|
1.
| (a) 4.47 |
(b) 4.5 |
| (c) 0.015 |
(d) 920 |
| (e) 5 |
(f) 0.73 |
| (g) 4.245 |
(h) 90 000 |
| (i) 56 |
(j) 190 |
| 2. |
 |
| (a) 48 000 people |
|
| (b) 12 kg |
|
| (c) $32 400 |
|
| (d)100 runs |
|
3.
|
Calculation
|
(a) Estimate
|
(b) Accurate answer
(rounded, if necessary, to 4 sig. fig.)
|
|
9.47 + 4.7
|
9 + 5 = 14
|
14.17
|
|
34.5 × 2.9
|
30 × 3 = 90
|
100.1
|
|
(9.42) 2
|
92 = 81
|
88.74
|
|
8.36⁄4.21
|
8/4 = 2
|
1.986
|
|
4.99 − (5.74 + 3.2)
|
5 − (6 + 3) = -4
|
-3.95
|
4.
(a) 4.8
(b) 4.50
(c) 0.10
(d) 7.294
(d) 427.3
(f) 50
5.
|
Purchase
|
Estimated cost
|
Accurate cost
|
|
4 cakes at $4.99 each
|
4 × 5 = $20
|
$19.96
|
|
2 buns at 99c each
|
2 × 1 = $2
|
$1.98
|
|
7 biscuits at 22 cents each
|
7 × 20 = $1.40
|
$1.54
|
|
2 cans of drink at $1.84 each
|
2 × 2 = $4
|
$3.68
|
|
4 loaves at $2.24 each
|
4 × 2 = $8
|
$8.96
|
|
Totals
|
$35.40
|
$36.12
|
|
