1. Which are the 5 ratios in this sequence? 95% 8/10 2:3 €3.50
Learning Objectives
To be able to simplify ratios
Which are the 5 ratios in this sequence?
95% 8/10 2:3 €3.50
3:4:6 € % 2/3
3/4 1:2:5:7 50cent 2:5
1:4 €0.80 4/8 33%

2. Learning Objectives
To be able to simplify ratios
Remember
A ratio compares values. It says how much of one thing there is compared to another thing.
1 to 3
1 : 3

3. What is the ratio of black counters to white?
_______
Simplify you answer _______
What is the ratio of white counters to black?
Shade in the counters to represent the given ratios of black to white.
4:1
2:5
1:3
5:3
7:2
6:5
5:1
3:2
7:5
1:1
2:4
6:2
1:2
3:1
4:3
2:10
4:3
1:5
9:3
15:3
3:1
5:1
3:6
3:3
1:2
1:1

4. L.O. To be able to simplify ratios
Including 3 parts, units & decimals!

5. Why does simplifying make sense?
What is the ratio of apple to oranges?
Apples : Oranges
6 : 9
2 : 3

6. Learning Objectives
To be able to simplify ratios
Simplifying Ratios
Ratios can be simplified by dividing each part by the highest common factor.
e.g. 7 : 21
So 1 : 3
7 is the highest common factor ÷𝟕 ÷𝟕

7. Learning Objectives
To be able to simplify ratios
Simplifying Ratios
For ratios with more than 2 parts, all parts must be divided by the same number.
e.g. 7 : 14 : 21
So 1 : 2 : 3
e.g. 3 : 12 : 24 : 36
So 1 : 4 : 8 : 12
7 is the highest common factor
3 is the highest common factor

8. Units Write this ratio in its simplest form: a.) 2m : 50cm
Like in everything else in Maths, we cannot work with the numbers if they do not have the same units!
It is always easier to change the larger units into the smaller
1m = 100cm , so 2m = 200cm
200 : 50
4 : 1
÷50

9. Decimals Write each ratio in its simplest form: b.) 2.5 : 1.5
When we have decimals, we always like to get rid of the point because it is easier to work with whole numbers!
How do we get rid of the points?
2.5 x 10 = x 10 = 15
25 : 15
5 : 3 ÷5

10. Mini-whiteboard Practise

11. Ratio of ..
Cows to Pigs

12. Ratio of
Apples to Bananas

13. Ratio of
Bieber to Rihanna

14. Ratio of
Football to Rugby

15. Ratio of..
Bike to Car

16. Simplify 120:600
1 : 5 (÷12)

17. 2. Simplify 56:64 7 : 8 (÷8)

18. 3. Simplify 30 cent : €1
€1 = 100 cent
30 : 100
3 : 10 (÷10)

19. 4. Simplify 600 m : 2 km
1 km = 1000 m
600 : 2000 (÷200)
3 : 10

20. 5. Simplify 1.4 : 3.5
14 : 35 (x 10)
2 : 5 (÷7)

21. 6. Simplify 0.2 : 0.24 : 3
20 : 24 : 300 (x 100)
5 : 6 : 75 (÷4)

22. 7. Simplify 0.08 : 0.4 : 1
8 : 40 : 100 (x 100)
2 : 10 : 25 (÷4)

23. Questions?