1.
| a | 8 |
| b | 400 |
| c | 2000 |
| d | 4.4 |
| e | 3.26 |
| f | 0.304 |
| 2. Round the following to the degree of accuracy stated: | ||
| (a) 16 744 people at a soccer match | 16700 (to the nearest hundred people) | |
| (b) A capacity of 3249 litres | 3250 (to the nearest ten litres) | |
| (c) A salary of $55,555 | $56, 000 (to the nearest thousand dollars) | |
| (d) A measurement of 9.959 metres | 9.96 metres (to the nearest centimetre) | |
3. (a) In the table below, round each number to 1 digit and calculate.
(b) Calculate the answer accurately and round it to 4 significant figures.
|
Calculation |
(a) Estimate |
(b) Accurate answer |
|
9.1 + 5.7 |
9 + 6 = 15 |
9.1 + 5.7 = 14.8 |
|
28 x 1.9 |
30 x 2 = 60 |
28 x 1.9 = 53.2 |
|
(8.4)2 |
82 = 64 |
8.4 x 8.4 = 70.56 |
|
16.98 − (4.75 + 8.1) |
20 − (5 + 8) = 7 |
16.98 − (4.75 + 8.1) = 4.13 |
4 .Round off the following numbers to the number of decimal places (d.p.) shown:
(a) 5.19 (to 1 d.p.) = 5.2
(b) 6.498 (to 2 d.p.) = 6.50
(c) 3.093 (to 1 d.p.) = 3.1
(d) 0.2949 (to 3 d.p.) = 0.295
(e) 927.295 (to 1 d.p.) = 927.3
(f) 50.94 (to 0 d.p.) = 51
5. Complete the table, by estimating the cost of each individual item to the nearest dollar and then calculating accurately.
|
Purchase |
Estimated cost |
Accurate cost |
|
4 loaves of bread at $2.95 each |
4 x $3 = $12 |
4 x $2.95 = $11.80 |
|
2 pies at $1.45c each |
2 x $1 = $2 |
2 x $1.45 = $2.90 |
|
7 biscuits at $0.85 cents each |
7 x $1 = $7 |
7 x $0.85 = $5.95 |
|
5 cans of drink at $1.75 each |
5 x $2 = $10 |
5 x $1.75 = $8.75 |
|
4 packets of chips at $1.45 each |
4 x $1 = $4 |
4 x $1.45 = $5.80 |
|
Totals |
$35 |
$35.20 |
