## Approximation and Estimation Exercise

1. Round off the following numbers to the nearest...

 a 8.4 to the nearest whole number b 359 to the nearest hundred c 2499 to the nearest thousand d 4.39 to the nearest tenth e 3.259 to the nearest hundredth f 0.3044 to the nearest thousandth

 2. Round the following to the degree of accuracy stated: (a) 16 744 people at a soccer match (to the nearest hundred people) (b) A capacity of 3249 litres (to the nearest ten litres) (c) A salary of \$55,555 (to the nearest thousand dollars) (d) A measurement of 9.959 metres (to the nearest centimetre)

3. (a) In the table below, round each number to 1 digit ( e.g. 17 becomes 20) and then calculate.

(b) Calculate the answer accurately and round it to 4 significant figures.

 Calculation (a) Estimate (b) Accurate answer 9.1 + 5.7 28 x 1.9 (8.4)2 16.98 − (4.75 + 8.1)

4.Round off the following numbers to the number of decimal places (d.p.) shown:
(a) 5.19 (to 1 d.p.)
(b) 6.498 (to 2 d.p.)
(c) 3.093 (to 2 d.p.)
(d) 0.2949 (to 3 d.p.)
(e) 927.295 (to 1 d.p.)
(f) 50.94 (to 0 d.p.)

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 2 pies at \$1.45c each 7 biscuits at \$0.85 cents each 5 cans of drink at \$1.75 each 4 packets of chips at \$1.45 each Totals