Numeracy Worksheet - Castlebrae Community High School - 2012 Page 34
ADVERTISEMENT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47FHS Numeracy
contents page
Ratio
Simplifying Ratios
Example 5
Simplify each ratio:
Divide all by 3.
Level 3
(a)
4 : 6
(b)
24 : 36
(c)
6 :3 : 12
4 : 6
24 : 36
6 : 3 : 12
÷ 12
÷ 2
÷ 12
÷ 2
2 : 3
2 : 3
2 : 1 : 4
Example 6 A ruler costs £1.20 and a pencil costs 40p.
When we compare two
Level 3
What is the ratio of the cost of a pencil
quantities in a ratio the
to the cost of a ruler?
numbers used must both be
in the same units.
pencil : ruler
40 : 120
÷ 4
÷ 4
1 : 3
Example 7 On a map 1cm represents 500m. Write this as a ratio.
Level 3
1cm : 500m
The units here are not the same.
Change m into cm (x 100)
1cm : 50 000cm
The units are now the same so drop the units
Ratio
1 : 50 000
to complete the ratio.
Using ratios
Example 8
The ratio of fruit to nuts in a chocolate bar is 3 : 2.
Level 3
If a bar contains 15g of fruit, what weight of nuts will it contain?
Fruit : Nuts
Fruit : Nuts
3
:
2
3
:
2
x 5
?
x 5
x 5
15 :
10
15 :
?
The chocolate bar contains 10g of nuts.
Whatever you do to one side you do the
same to the other side. (x 5)
(ONLY x or ÷ )
34
L Watson 2012
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education