Dŵr y Felin Comprehensive School
Key Stage 3
Numeracy in Registration - Homework
Name ……………………………………..
FOUR RULES OF NUMBER
Remember – It is often easier to work out the answer to a question if you set out the
sum in the correct way.
Examples
1. 3451 + 817
3451
+ 817
4268
2.
3 1
438 – 392
4 38
392
046
-
1
3. 34 x 7
x
34
7
23 8
4.
276 x 26
x
2
276
26
1 64536
51512 0
7176
1
5.
687 ÷ 3
229
3 6 827
Exercise
892
1.
810 + 81
=
=
19 x 19
10.
819 + 2800 =
11.
904 - 730
=
174
12.
44.7 x 0
=
0
13.
231 x 10
= 2310
14.
25 x 17
=
425
=
405
4778
2.
4230 + 548 =
3.
536 - 70
=
4.
36 ÷ 6
=
5.
18 x 22
=
6.
982 -156
=
7.
50 ÷ 5
=
10
15.
872 - 467
8.
24 x 8
=
192
16.
29.9 + 3
466
6
396
826
361
9.
=
3619
32.9
FRACTION OF AN AMOUNT
To find a fraction of an amount we divide by the denominator (bottom) and then
multiply by the numerator (top)
Examples
1. ½ of 30 = 30 = 15
2
3.
2
5
of 30 = 30 = 6
5
=6x2
= 12
2.
1
4.
3
7
8
of 42 = 42 = 6
7
of 48 = 48 = 6
8
=6x3
= 18
Exercise
9.
1
8
10.
3
of 70 =
7
11.
2
of 16 =
8
6
12.
1
1.
½ of 60=
2.
1
3.
4.
of 64 =
8
1
10
3
30
3
of 80 =
24
13.
6.
3
of 25 =
15
7.
5
of 18 =
6
8.
1
5.
10
5
8
of 40 =
of 88
=
of 24
4
=
4
5
of 35
=
of £160 =
8
22
18
14
£20
9
of 99 =
14.
1
of 380m = 190
15
15.
3
of $28 = $12
5
16.
11
2
7
2
3
of 96
81
= 64
ROUNDING
Examples
Round the following numbers to the number of decimal places in brackets.
37.178 (1 decimal place) = 37.178 = 37.2
56.353 (2 decimal places) = 56.353 = 56.35
38.9010 (3 decimal places) = 38.9010 = 38.901
If the number that is underlined is greater or equal to 5, the number that is bold
rounds up one. If the number that is underlined is less than 5 then it is ‘chopped off’
Exercise
1.
4.123(1decimal place)
=
4.1
2.
64.892 (1decimal place)
=
64.9
3.
7.901 (2 decimal places)
=
7.90
4.
4.932 (2 decimal places)
=
4.93
5.
73.9912 (3 decimal places) =
73.991
6.
6.9009 (3 decimal places) =
6.901
7.
71.1928 (3 decimal places) =
71.193
8.
7.102 (1 decimal place)
7.1
9.
28.837 (2 decimal places) =
28.84
10.
18.728 (1 decimal place)
18.7
11.
12.0003 (3 decimal places) =
12.000
12.
4.99
5.0
place)
(1
=
=
=
decimal
MULTIPLYING DECIMALS
0.3 has one number after
the decimal point, 0.2 also
has one number after the
decimal point.
So the
answer must have 2
numbers after the decimal
point.
Examples.
1. 0.3 x 0.2 = 0.06
2. 0.7 x 4 = 2.8
0.7 has one number after
the decimal point, 4 is a
whole number so doesn’t
have any numbers after the
decimal point.
So the
answer must have 1
number after the decimal
point.
Exercise
Work out the following multiplication sums. Be careful where you place the decimal point in each
answer!
1.
0.6 x 3
= 1.8
2.
5 x 0.6
=
3.
0.4 x 0.8 =
3.0
0.32
7. 0.5 x 0.08
=
8. 0.07 x 0.7
=
9. 0.2 x 0.009
=
0.01
4.
0.1 x 0.1 =
10. 1.4 x 0.6
0.7 x 0.2 =
0.05 x 9 =
0.0018
=
1.30
11. 2.6 x 0.5
=
0.45
6.
0.049
0.84
0.14
5.
0.040
0.144
12. 2.4 x 0.06
=