1. Round off the following numbers to the number of significant figures shown in brackets:
| (a) 4.472 (to 3 sig. fig.) | (b) 4.49 (to 2 sig. fig.) |
| (c) 0.0147 (to 2 sig. fig.) | (d) 924.4 (to 2 sig. fig.) |
| (e) 4.794 (to 1 sig. fig.) | (f) 0.729 (to 2 sig. fig.) |
| (g) 4.2447 (to 4 sig. fig.) | (h) 92444 (to 1 sig. fig.) |
| (i) 2.79 × 20.2 (to 2 sig. fig.) | (j) 9.42 × 20 (to 2 sig. fig.) |
| 2. Round the following to the degree of accuracy stated: |  |
|
| (a) 47 744 people at a football match (to the nearest thousand people) | ||
| (b) A mass of 12.49 kg (to the nearest kg) | ||
| (c) A salary of $32,449 (to the nearest hundred dollars) | ||
| (d) A cricketer's score of 99 (to the nearest ten runs) | ||
3. (a) In the table below, round each number to 1 significant figure and calculate.
(b) Calculate the answer accurately and round it to 4 significant figures.
|
Calculation |
(a) Estimate |
(b) Accurate answer (rounded to 4 sig. fig.) |
|
9.47 + 4.7 |
||
|
34.5 × 2.9 |
||
|
(9.42) 2 |
||
|
8.36⁄4.21 |
||
|
4.99 − (5.74 + 3.2) |
4.Round off the following numbers to the number of decimal places (d.p.) shown:
(a) 4.79 (to 1 d.p.)
(b) 4.497 (to 2 d.p.)
(c) 0.097 (to 2 d.p.)
(d) 7.2944 (to 3 d.p.)
(e) 427.2994 (to 1 d.p.)
(f) 49.94 (to 0 d.p.)
5. Complete the table, by estimating the cost of each item to 1 significant figure:
|
Purchase |
Estimated cost |
Accurate cost |
|
4 cakes at $4.99 each |
||
|
2 buns at 99c each |
||
|
7 biscuits at 22 cents each |
||
|
2 cans of drink at $1.84 each |
||
|
4 loaves at $2.24 each |
||
|
Totals |
