Year 4 Numeracy
With Mr Marcus
Ratio
Ratio is the relationship
between two or more quantities.
The symbol for ratio is (:)
Expressing ratios in their
simplest forms
Example 1: Express the following
ratios in their simplest form.
(a) 75cm to 1m
(b) 2 ⅟2 hrs : 55min
(c) 560g : 2.1kg
Ratio
Ratio is the relationship between
two or more quantities. The symbol
for ratio is (:)
Expressing ratios in their simplest
forms
Example 1: Express the following
ratios in their simplest form.
(a) 75cm to 1m
(b) 2 ⅟2 hrs : 55min
(c) 560g : 2.1kg
solution
(a) Note: 1m= 100cm
75cm : 1m
75cm : 100cm
15 : 20
3:4
Ratio
(b) 2⅟₂hrs : 55
Ratio is the relationship between
60 mins = 1hr
two or more quantities. The symbol
2⅟₂hrs : 55
for ratio is (:)
⁵⁄₂ x 60 : 55
150 : 55
Expressing ratios in their simplest
30 : 11
forms
(c) 560g : 2.1kg
Example 1: Express the following
1000g = 1kg
ratios in their simplest form.
(a) 75cm to 1m
560g : 2.1kg
(b) 2 ⅟2 hrs : 55min
560g : 2.1 x 1000
(c) 560g : 2.1kg
560g : 2100g
solution
8 : 30
(a) Note: 1m= 100cm
4 : 15
75cm : 1m
Comparison of ratios
75cm : 100cm
Example 2: which of this pair 2:3 or
15 : 20
3:4 is greater?
3:4
⅔ : ⅗
Ratio
Example 3 : Arrange these ratio 5:12,
1:3, 5:6, 3:5.
Solution
5/12 , 1/3, 5/6, 3/5
25, 20, 50,36
60
In ascending order: 1/3, 5/12, 3/5,
5/6= 1:3, 5:12, 3:5, 5:6
Equivalent Ratios
Example 4: express two equivalent
ratios for each of these ratios
(a) 3:8 (b) 4:5
Solutions
(a) 3 x 2 : 8 x 2
3 x3 : 8 x 3
6:16
9:24
(b) 4x2 : 5 x 2
4x3:5x3
8:10
12:15
Converting Fraction Ratios to
whole numbers
example 5: Convert the following
fraction ratio to whole number
(a) ¾ : 3/8 (b)5/7 : 5/6 (c) 7½ : 2¾
solutions
(a) ¾ : 3/8
(b)5/7 : 5/6
6:3
30:35
8
42
=6:3
= 30 : 35
(c) 7½ : 2¾
15/2 : 11/4
30:11
4
= 30 : 11
Ratio
Evaluation
1. Express the following ratios in their simplest form
(a) 35cm to 1m (b) 3¼hrs : 55min (c) 560g : 2.4kg
2. Which of this pair 5:7 or 6:8 is greater?
3. Convert the following fraction ratios to whole number
(a) ¼ :3/7 (b) 5/6 : 3/8 (c) 2¾ : 1⅔
4. Express two equivalent ratios for each of these ratios
(a) 5:7 (b) 3:8 (c) 1:4
5. In a house there 8 women and 12 men.
a. What is the ratio of the number of men to the number of women?
b. what is the ratio of the number of women to the numbers of
men?
Ratio
Ratio is the relationship between
two or more quantities. The
symbol for ratio is (:)
Express
Ratio
Ratio is the relationship between
two or more quantities. The
symbol for ratio is (:)
Express
Ratio
Ratio is the relationship between
two or more quantities. The
symbol for ratio is (:)
Express