1. 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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2. 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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3. 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 1.04 × 105
B 1.04 × 109
C 3.47 × 105
D 3.47 × 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 4 × 103
B 4 × 104
C 6.9 × 103
D 6.9 × 104
4. Express 0.0000405 in standard form.
A 4.05 × 10-5
B 4.05 × 105
C 405 × 10-7
D 405 × 107
9 ⋅ 28 × 10 −2
5. =
(4 × 10 )
−3 2
A 2 ⋅ 32 × 10 3
B 2 ⋅ 32 × 10 4
C 5 ⋅ 8 × 10 3
D 5 ⋅ 8 × 10 4
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4. ppr maths nbk
6. 5 ⋅ 34 × 10 −7 − 3 ⋅ 7 × 10 −8 =
A 1 ⋅ 64 × 10 −8
B 1 ⋅ 64 × 10 −7
C 4 ⋅ 97 × 10 −8
D 4 ⋅ 97 × 10 −7
7. Round off 0 ⋅ 07207 correct to three significant figures.
A 0 ⋅ 07
B 0 ⋅ 072
C 0 ⋅ 0720
D 0 ⋅ 0721
8. Round off 80725 correct to three significant figures.
A 80700
B 80720
C 80730
D 80800
9. Express 9 ⋅ 9263 × 10 −6 as a single number.
A 0 ⋅ 009263
B 0 ⋅ 0009263
C 0 ⋅ 00009263
D 0 ⋅ 000009263
0 ⋅ 02
10. =
4000000
A 5 × 10 3
B 5 × 10 4
C 5 × 10 −8
D 5 × 10 −9
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