1. to the nearest ......... Write each (i) to the nearest ten
(ii) to the nearest hundred
= 8360
(to nearest ten)
= 8400
(to nearest hundred) = = = =
4. 34
= 30
= 0 = =
= 30
= 0
= 430
= 400
= 820
= 800
= 100
= 100
= 2 560
= 2 600

2. to the nearest ......... Write each (i) to the nearest tenth
(ii) to the nearest whole
= 42.6
(to nearest tenth)
= 43
(to nearest whole)
= 157.9
= 158
= 4.7
= 5
= 27.1
= 27 =
= 2 474
= 26.8
= 27
= 425.3
= 425
= 816.5
= 816
= 95.8
= 96 =
= 2 556

3. Significant Figures 2 significant figures 3 significant figures 45
0.0062
to nearest
million
3 significant figures
to nearest
whole
to 4 dec pl
27.3
to nearest 1000
to nearest tenth
to nearest
hundred thousandth
4 significant figures
to 1 dec pl
7002
to 5 dec pl
5.308
56.0
3050
to 3 dec pl
to nearest tenth
to nearest ten
to 5 dec pl

4. Round each of the following to 3 significant figures
34 629
73 579
1347
45.666
2.8369
34 600
73 600
1350
45.7
2.84
173.92
9044
12.345
174
9040
0.0497
12.3
47.73
31.655
919.9
2547
47.7
31.7
920
2550
Round each of the following to 2 sig fig
31.793
258.6
91 832
428
129.3
2040
1.036
35.67 32
260
92 000
430
0.086
130
2000
1.0 36

5. Use the calculator for standard formEE
Exp or
on scientific calculator
5.3 03
in place of x 10n
on display means 5.3 x 103
5.3 x x x 104
5.3Exp3 x 2.7Exp4 =
1.431 x 108
without calculator / estimate
2.83 x 102 x x 103
5 x x 3 x 104
estimate
3 x 9 x 102 x 103
= 5 x 3 x 103 x 104
27 x 105 = 2.7 x 106
= 15 x 107
= x 106
= 1.5 x 10 x 107
= 2.59 x 106
to 3 sig fig
= 1.5 x 108

6. …% of ……… Percentages 1/2 1/4 1/5 1/10 1/100 1/3 50% of £658
50% = =
1/2
÷ 2
= ÷ 2
25% = =
1/4
÷ 4
= 329
20% = =
1/5
÷ 5
10% = =
1/10
÷ 10
1% of 7382 kg
= ÷ 100
1% = =
1/100
÷ 100 =
331/3% =
1/3
÷ 3
13% of £67
= x 67
13% = 0.13
= 8.71

7. Express as a percentage of ...
35 marks out of total 56
35 ÷ 56 x 100 35 56
x 100
So Pupil’s mark was 62.5%
= 62.5%
Item costs £45 and sells for £54.
Express the profit as a percentage of the cost price.
S P = 54
C P = 45
Profit = 9
9 ÷ 45 x 100 9 45
x 100
= 20 %
So Profit was 20% of the cost price.