Transcript Unit 1 Revision

Write each (i) to the nearest ten
(ii) to the nearest hundred
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
8357
80 548
245 632
34
764 799
26.83
425.28
816.4
95.8
2 555.5
= 8360 (to nearest ten) = 8400 (to nearest hundred)
= 80 550
= 80 500
= 245 630
= 245 600
= 30
=0
= 764 800
= 764 800
= 30
=0
= 430
= 400
= 820
= 800
= 100
= 100
= 2 560
= 2 600
M May
Write each (i) to the nearest tenth
(ii) to the nearest whole
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
42.57
= 42.6 (to nearest tenth) = 43 (to nearest whole)
157.93
= 157.9
= 158
4.6835
= 4.7
=5
27.06
= 27.1
= 27
2 473.888 = 2 473.9
= 2 474
26.83
= 26.8
= 27
425.28
= 425.3
= 425
816.49
= 816.5
= 816
95.807
= 95.8
= 96
2 555.555 = 2 555.6
= 2 556
M May
2 significant figures
56 000 000
3 significant figures
378 000
to nearest 1000
56.0
27.3
to nearest tenth
to 1 dec pl
3050
to nearest
million
45
to nearest
whole
0.0062
to 4 dec pl
0.005 32
to nearest
hundred thousandth
to 5 dec pl
4 significant figures
7002
5.308
0.004 07
to 3 dec pl
to nearest tenth
to nearest ten
to 5 dec pl
M May
Round each of the following to 3 significant figures
34 629
34 600
73 579
73 600
1347
1350
45.666
45.7
2.8369
2.84
173.92
174
0.004683
0.00468
9044
9040
0.04968
0.0497
12.345
12.3
0.000 083 76
0.000 083 8
47.73
47.7
31.655
31.7
919.9
920
2547
2550
Round each of the following to 2 sig fig
8 776 341
8 800 000
0.085 726
0.086
31.793
32
129.3
130
258.6
260
2040
2000
91 832
92 000
1.036
1.0
428
430
35.67
36
M May
EE
or
in place of
Exp
x
on scientific calculator
5.3
10n
03
on display means 5.3 x 103
5.3 x 103 x 2.7 x 104
= 1.431 x 108
without calculator / estimate
5 x 103 x 3 x 104
= 5 x 3 x 103 x 104
= 15 x 107
= 1.5 x 10 x 107
= 1.5 x 108
5.3Exp3 x 2.7Exp4
2.83 x 102 x 9.167 x 103
estimate
3 x 9 x 102 x 103
27 x 105 = 2.7 x 106
= 2.594261 x 106
= 2.59 x 106 to 3 sig fig
M May
…% of ………
50% = 0.50 =
1/
2
÷2
25% = 0.25 =
1/
4
÷4
20% = 0.20 =
1/
5
÷5
10% = 0.10 =
1/
10
÷ 10
1% = 0.01 =
1/
100
÷ 100
331/3%
13% = 0.13
= 1/ 3
50% of £658
= 658 ÷ 2
= 329
1% of 7382 kg
= 7382 ÷ 100
= 73.82
÷3
13% of £67
= 0.13 x 67
= 8.71
M May
35 marks out of total 56
35 ÷ 56 x 100
35 x 100
56
= 62.5%
So Pupil’s mark was 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.
M May