1. Starter activity 60/80 7/21 21/70 90/100 240/480
Simplify the following fractions on a whiteboard.
3/6
2/4
4/8
6/8
60/80
7/21
21/70
90/100
240/480

2. Ratio and Proportion

3. L/O:
To know the difference between ratio and proportion.
To solve simple ratio and proportion problems.

4. What is ratio?
Ratio is a way of comparing two quantities, for example:
The ratio of red to blue is 1:3
This can also be said as:
“For every 1 red block there are 3 blue blocks.”
The ratio of red to blue is
2:6

5. For every red cube how many blue cubes are there?
For every 1 red cube there are three blue cubes.
Ratio of 1 to 3
1:3 This symbolic representation has the same meaning as the word statement but it read as ‘1 to 3’.
The smaller number is usually written first in a ratio.

6. What is proportion? What proportion of cubes are blue? ¼
Proportion is when you compare parts of a whole and is written as a fraction, for example:
The proportion of red blocks is ¼
This can also be said as: “In every 4 blocks 1 is red.”
What is the proportion of blue blocks?
What proportion of cubes are blue?

7. How many red cubes are there in every 4 cubes?
1 in every 4 cubes is red. This shows the proportion of red cubes to the whole number of cubes and can be written as a fraction
¼ of the cubes are red.
What proportion of the cubes are blue?

8. So, we’ve compared the number of blue and red cubes in two different ways
Remember:
RATIO (For every) compares one amount with another
e.g 1:3.
PROPORTION (In every) is when you compare parts of a whole and is written as a fraction.
e.g 1/4

9. What is the ratio of blue to green?
2:3
What is the proportion of blue cubes? = 5
What is the proportion of green cubes?

11. If Mark has 2 stamps and John has 4, what ratio is this?
2 : 4
1 : 2
If Mark has 200 stamps and John has 400 stamps what ratio is this?
200 : 400  2 : 4  1:2
If William has 500 sweets and Becky has 1000 sweets, what ratio is this?
500 : 1000  5 : 10  1 :2

12. There are ten biscuits on a plate
There are ten biscuits on a plate. Three of them are chocolate and seven are plain.
What is the ratio of chocolate to plain biscuits?
There are 3 chocolates for every plain biscuit :7
What proportion of the biscuits are chocolate?
3 of the 10 are chocolate 3 in 10 3/10
What proportion of the biscuits are plain?
7 of the 10 are plain 7 in 10 7/10

13. RATIO (For every) compares one amount with another
Ratio and Proportion
Remember:
RATIO (For every) compares one amount with another
e.g 1:3.
PROPORTION (In every) is when you compare parts of a whole and is written as a fraction.
e.g ¼

14. How many boys are in our class? How many girls?
What is the ratio of boys to girls?
What proportion of the class is boys?
What proportion is girls?

15. During this activity you will have used the following skills:
Key Skills Used
During this activity you will have used the following skills:
Knowledge related to ratio and proportion.
Knowledge of fractions.
Knowledge of multiplication tables.
Ability to apply all of the above to a specific context or word problem.