Standard Form

ppr maths nbk

CHAPTER 1 : STANDARD FORM EXERCISE 2 1. Round off each of the following numbers to 3 significant figures. (a) 2963

= __________________

(b) 51852

= __________________

2. Round off 71.65 to (a) 3 Significant figures

= __________________

(b) 1 Significant figures

= __________________

3. Round off 0.06053 to (a) 3 Significant figures

= __________________

(b) 2 Significant figures

= __________________

(c) 1 Significant figures

= __________________

4. Express each of the following numbers in standard form (a)

48000

= ___________________

(b)

9200.05

= ___________________

(c)

0.026

= ___________________

(d)

0.00000038

= ___________________

5. Convert the following numbers in standard form to a single number. (a) 2.19 × 10 3

= ___________________

(b) 8.2 × 10 −4

= ___________________

6. Evaluate each of the following and express your answers in standard form. (a) 16000000 + 2500000

= ____________________

(b) 0.69 + 10.451

= ____________________

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ppr maths nbk

7. Evaluate each of the following and express your answers in standard form. (a) 920000 – 87000

= ____________________

(b) 0.043 – 0.00095

= ____________________

8. Evaluate each of the following and express your answers in standard form. (a) 4.8 × 700

= ____________________

(b) 0.0029 × 0.065

= ____________________

9. Evaluate each of the following and express your answers in standard form. (a) 48.6 × 0.03

= ____________________

(b) 0.000096 ÷ 0.04

= ____________________

10. Given that the mass of a carbon atom and an oxygen atom are 2 × 10 −23 g and 2.7 × 10 −23 g respectively, one molecule of carbon dioxide gas consist of one carbon atom and two oxygen atoms. Calculate the mass in gram, of one molecule of carbon dioxide gas. Answer : _________________

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ppr maths nbk

CHAPTER 1 : STANDARD FORM DIAGNOSTIC TEST

1. Round off 0.0487 correct to two significant figures. A 0.04 B 0.05 C 0.048 D 0.049 2. 2.7 × 10 5 + 77000 = A B C D

1.04 1.04 3.47 3.47

× × × ×

105 109 105 109

3. The area of a rectangular plot of land is 9.2 km2. Its width is 2300 m. Find the length, in m, of the plot of land. A B C D

4 × 103 4 × 104 6.9 × 103 6.9 × 104

4. Express 0.0000405 in standard form. A B C D

5.

4.05 × 10-5 4.05 × 105 405 × 10-7 405 × 107

9 ⋅ 28 × 10 −2

(4 × 10 )

−3 2

A B C D

=

2 ⋅ 32 × 10 3 2 ⋅ 32 × 10 4 5 ⋅ 8 × 10 3 5 ⋅ 8 × 10 4

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ppr maths nbk

6. 5 ⋅ 34 × 10 −7 − 3 ⋅ 7 × 10 −8 = A B C D

1 ⋅ 64 × 10 −8 1 ⋅ 64 × 10 −7 4 ⋅ 97 × 10 −8 4 ⋅ 97 × 10 −7

7. Round off 0 ⋅ 07207 correct to three significant figures. A B C D

0 ⋅ 07 0 ⋅ 072 0 ⋅ 0720 0 ⋅ 0721

8. Round off 80725 correct to three significant figures. A B C D

80700 80720 80730 80800

9. Express 9 ⋅ 9263 × 10 −6 as a single number. A B C D

10.

0 ⋅ 009263 0 ⋅ 0009263 0 ⋅ 00009263 0 ⋅ 000009263

0 ⋅ 02 = 4000000 A B C D

5 × 10 3 5 × 10 4 5 × 10 −8 5 × 10 −9

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