DECIMALS

1. Using a calculator, or otherwise, evaluate to 3 decimal places: 1.6  3.89 4.54  3.21 0.832  0.032. Find the exact value of 0.0243. Evaluate 0.2704 10.02  0.14 a. 0.7  50.1 b. Evaluate using a calculator4. Without using a calculator, calculate the exact value of 0.28(5  3.95) 0.5  0.141

5. a) Find the exact value of  7.5  6.3 2.55 1.25 b) Write your answer correct to one decimal place6. Without using a calculator calculate the exact value of 26.32  38.8 13.16 11.567. Calculate the exact value of (i)0.25 ÷ 0.4 (ii) 5(7 – 1.43) 0.098. Calculate 400  1.6 103 2  9. a) Evaluate  0.4  b) Express your answer in standard form. 0.02310. Evaluate 0.351 and give your answer to 2 significant figures.11. Evaluate 3.2 105  2.5 103 and give your answer in standard form. 2

12. Evaluate 0.0004 102 , giving your answer in standard form.13. Write the number 74.498 correct to i. the nearest whole number ii. three significant figures iii. two decimal places14. Determine to three significant figures i. the square root of 13 ii. the reciprocal of 1315. Evaluate 2.7 103  5.3 102 , giving your answer in standard form.Workings for questions 1, 4 and 11 are shown:1. Working shown 1.6  3.894.54  3.21 5.49 1.33 4.1278195... 4.128 to 3 d.p. 3

2. 1.043. a) 0.04 b) 0.52 6. 40.74. Working shown 7. (i) 0.625 (ii) 27.85 8. 0.015 49 9. a) 16,000,000 5  3.95  5 . 10 10 b) 1.6 x 107 10. 0.065527065 -3.9 5 0.066 to 2 s.f. 1.0 5 11. Working shownNumerator: (3.2 105)  (2.5 103)0.28(5  3.95)  0.28 1.05  (3.2  2.5) 1053 1.05  1.28 102  0.28 12. 0.002 0.0840 13. (i) 74 (ii) 74.5 3 s.f. + 0.210 (iii) 74.50 0.2940 14. (i) 3.6055512..Denominator: 3.61 to 3 s.f.0.5  0.14  0.14 (ii) 0.0769223  0.5 0.0769 to 3 s.f. 0.070 15. 2,170Solution:0.294  0.07  29.4  7 4.2 7 29.45. a)10.065 b) 10.1 4