1. Ratio
3 : 7

2. If we write the pairs of numbers as fractions we get the following:= = = = = = = = = 40 1 2 3 4 5 6 7 8 9 12 16 20 24 28 32 36 10 = = = = = = = = =

3. What do YOU notice? 2 + 3 + 5 = 10 4 + 6 + 10 = 20 6 + 9 + 15 = 30
Top line x 2
= 20
= 30
Top line x 3 40 6 9 15 8 12 20 30
Top line x 4
= 40

4. What is in a ratio of 2:3:5 20 2 3 5 4 6 10 Question:
20 sweets are split up in a ratio of 2:3:5 between 3 friends Bill, Ben & Jerry. How many did Ben get?
WHY?
How do you know you are right? 40 6 9 15 8 12 20 30

5. What is in a ratio of 2:3:5 20 2 3 5 4 6 10 Question:
30 pounds is split up in a ratio of 2:3:5 between 3 friends Bill, Ben & Jerry. How many did Ben get?
WHY?
How do you know you are right? 40 6 9 15 8 12 20 30

6. What is in a ratio of 2:3:5 20 2 3 5 4 6 10 Question:
50 marbles are split up in a ratio of 2:3:5 between 3 friends Bill, Ben & Jerry. How many did Ben get?
WHY?
How do you know you are right? 40 6 9 15 8 12 20 30

7. What is in a ratio of 2:3:5 20 2 3 5 4 6 10 Question:
WHY?
How do you know you are right? 40 6 9 15 8 12 20 30

8. Card activity Split into two groups
Find the odd one out in your groups card set
Discuss why this is the case
Elect someone to feedback
Look at the other card set that the other group had discuss what the differences and similarities

9. Which one is the odd one out?

10. Which one is the odd one out?
WHY?

11. Which is the odd one out?
8:12
4:6
18:27
20:30
6:10
22:33
2:3
10:15
6:9
14:21

12. Which is the odd one out?
8:12
4:6
18:27
20:30
6:10
WHY?
22:33
2:3
10:15
6:9
14:21

13. Ratios can be simplified in the same way fractions can be simplified
9:12
= 6:8
= 3:4
Fractions
These can be described as equivalent ratios.
These are know as equivalent fractions.

14. Ratios can also be written as fractions
Strategy
Add the ratios together – get the total
Write each of the ratios in fraction form over the total
E.g. the ratio 3:4
Add the ratios 3+4 = 7
The ratio can be written in fraction form as: and

15. Ratios describe some thing else. Example of what they can be used for
Draw two lines of equal length, label one ratio and the other what ever it is describing
Use the lines as scales and add the information that you know.
The angles of a triangle are in a ratio of 2:3:4 2 3 4
Total
Ratio 9 ? ? ?
Degrees
In a triangle
180

16. What we get are equivalent fractions= = = = = = = = = 40 1 2 3 4 5 6 7 8 9 12 16 20 24 28 32 36 10 = = = = = = = = =

17. The angles of a triangle are in a ratio of 2:3:4 What are they?
therefore
Multiply both sides by the number that divides the ? 2 3 4
Total
Ratio 9 ? ? ?
Degrees
In a triangle
180

18. Read the Question
Extract the information (ratios are on the same line)
Write the calculation (use equivalent fractions)
Write the answer in context to the question

19. Strategy
Question
In a shop the ratio of oranges to apples is 2:5. If there are 84 pieces of fruit altogether, how many oranges are there?
Lines to extract information
ratio
Lines to extract information 2 5 8
fruit ? ? 84
Equivalent fraction is
Calculation
Answer – in context to the question.
There are 21 oranges in the shop.

20. What do you remember about ratio
3:4 is read 3 to 4
Ratio can be simplified in the same way fractions are
Ratios can be written as fractions
Ratios describe the make up of some group of objects
Ratios can be used to find actual quantities