Decimal and Significant Figures

1. Round off the following according to questions
(a) 68786 (to the nearest thousands place)
(b) 74245 (to the nearest hundreds place)
(c) 99999 (to the nearest tens place)
(d) 76175 (to the nearest thousand place)

2. Round off the following according to the Questions
(a) 78.8 (tens place)
(b) 888 (tens place)
(c) 3213 (hundreds place)
(d) 8357.65 (hundred place)
(e) 87.6 (once place)

3. Round off the following according to the questions
(a) 9.6 (one place)
(b) 995.4 (hundred place)
(c) 35.4 (tens place)
(d) 0.43 (one place)

4. Round off the following according to the questions
(a) 123.452 (1 d.p.)
(b) 493.7598 (2 d.p)
(c) 97.69 (tenths place)
(d) 0.3974 (hundredths place)
(e) 44.742 (2 d.p)
(f) 265.953 (1 d.p)

5. An athlete’s time for a race was 43.78secods.
(a) Write this time correct to
(i) One decimal place
(ii) Correct to tens

(b) Write 43.78 and answers to (a) part (i) and (ii) in the ascending order.

6. Change to decimal. Write down calculator display correct to 4dp.
7. A car costs £7552. Write the cost of the car nearest 100pounds.

8. The mass of a bottle is 483gms. Write the mass correct to hundred grams.

9. Round off the following numbers correct to the number of significant figures indicated within brackets.
(a) 8.043 (2s.f.)
(b) 4.13865 (2s.f.)
(c) 0.04036 (1s.f)
(d) 0.03064 (3s.f)
(e) 64.074 (1s.f)
(f) 71.97 (3s.f)
(g) 2467 (2s.f)

10. Calculate the following and write correct to 1s.f
(a)
(b)
(c)(4.742+6.292)3
(d) 11. The diameter of the sun is 1 392 530 kilometres. Write this value correct to 4 significant figures.

12. Write the number 2381.597 correct to
(a) 3 significant figures,
(b) 2 decimal places, (c) the nearest hundred.