1. Intro Which are the 5 ratios in this sequence? 95% 8/10 2:3 £3.50
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Intro
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 50p 2:5
1:4 £0.80 4/8 33%
Ratio Mr Martin February 2014

2. Where are you now? I know quite a bit about ratio
I’ve seen or heard of ratio before
Not sure what ratio is

3. Key words/ Literacy Skills:
We are learning about:
Ratio
We are learning to:
Use ratio notation, reduce a ratio to its simplest form and divide a quantity into two parts in a given ratio
Success criteria:
Can reduce a ratio to its simplest form (Level 5)
Able to divide a quantity into two or more parts in a given ratio (Level 6)
Maths 17/09/2018
Key words/ Literacy Skills:
Highest Common Factor
Real world problems – Sharing money

4. Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Intro
A ratio compares values. It says how much of one thing there is compared to another thing.
1 to 3
1 : 3
Ratio Mr Martin February 2014

5. Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
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
Ratio Mr Martin February 2014

6. Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
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
Ratio Mr Martin February 2014

7. Simplifying Ratios Remember that units are important as is order.
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Simplifying Ratios
Remember that units are important as is order.
e.g. 30mm : 4cm We need to convert so both sides are in the same unit, so
30mm : 40mm
e.g. 2 : 5 is not the same as 5 : 2
Why?
Ratio Mr Martin February 2014

8. Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Simplifying Ratios
On your own, work through the questions on the front of the handout sheet.
Green questions are the easiest, please try these to start
Orange questions are a bit trickier
Red questions are saved for when you have really mastered things
Extension – Create your own ratios for a partner to simplify
Ratio Mr Martin February 2014

9. Answers Green Orange Red 4) 2 : 3 8) 1 : 3 12) 2 : 1 1) 1 : 2 5) 2 : 3
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Answers
Green
Orange
4) 2 : 3
8) 1 : 3
12) 2 : 1
1) 1 : 2
5) 2 : 3
9) 1 : 10
13) 1 : 2
2) 3 : 2
6) 1 : 2
10) 1 : 2
14) 2 : 1
3) 1 : 2
7) 1 : 2
11) 1 : 4
15) 1 : 2
Red
4) 3 : 1
8) 4 : 1
1) 3 : 4 : 6
5) 4 : 1
9) 10 : 7
2) 1 : 2 : 3
6) 1 : 5
10) 7 : 10
3) 1 : 1 : 3
7) 4 : 3
11) 1 : 3
1) 1 : 3 : 5 : 8
4) 2 : 6 : 3 : 5
2) 3 : 5
5) 5 : 2 : 3
3) 1 : 3
6) 2 : 1 : 1
Ratio Mr Martin February 2014

10. How did you do? All or almost all answers correct
Most answers correct, some errors
Majority of answers incorrect

11. Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Dividing by a ratio
Often we might need to divide an amount by a ratio.
e.g. Divide £50 into the ratio 2 : 3
There are some common steps to allow us to work this out
Ratio Mr Martin February 2014

12. Dividing by a ratio Steps to Success
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Dividing by a ratio
Steps to Success
Add together the total number of parts of the ratio
Divide the given amount by the total number of parts
Multiply the answer by each ratio amount
Check that your answers add up to the same total given in the question
Ratio Mr Martin February 2014

13. Dividing by a ratio Divide £50 into the ratio 2 : 3
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Dividing by a ratio
Divide £50 into the ratio 2 : 3
Add together the total number of parts of the ratio
Divide the given amount by the total number of parts
Multiply the answer by each ratio amount
Check that your answers add up to the same total given in the question
(2 + 3 = 5)
(50 ÷ 5 = 10)
(10 x 2 = 20 and 10 x 3 = 30)
( = 50 )
Ratio Mr Martin February 2014

14. Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Dividing by Ratios
On your own, work through the questions on the back of the handout sheet.
Green questions are the easiest, please try these to start
Orange questions are a bit trickier
Red questions are saved for when you have really mastered things
Extension – Create your own values for a partner to divide by a ratio
Ratio Mr Martin February 2014

15. Answers Green Orange Red 1) £10 : £40 2) 10 litres : 30 litres
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Answers
Green
Orange
1) £10 : £40
2) 10 litres : 30 litres
3) £4 : £6
4) 200g : 300g
5) 30ml : 70ml
6) 10cm : 20cm
1) 28p : 14p : 7p
2) £200 : £100 : £50
3) £75 : £150 : £25
4) 20cm : 40cm : 60cm
5) 17g : 34g
6) 17p : 34p : 17p
Red
1) 50 indie : 70 dance
2) 30 scientific : 6 ordinary
3) 800 boys : 600 girls
4) 100 adults : 80 children
Ratio Mr Martin February 2014

16. How did you do? All or almost all answers correct
Most answers correct, some errors
Majority of answers incorrect

17. Ratio Bingo
Cows to Pigs
Ratio Mr Martin February 2014

18. Ratio Bingo
Apples to Bananas
Ratio Mr Martin February 2014

19. Ratio Bingo
Bieber to Rihanna
Ratio Mr Martin February 2014

20. Ratio Bingo
Football to Rugby
Ratio Mr Martin February 2014

21. Ratio Bingo Bike to Car (in its simplest form)
Ratio Mr Martin February 2014

22. Ratio Bingo Divide £50 into the ratio 2:3
Ratio Mr Martin February 2014

23. Ratio Bingo John has 273 Facebook Friends
John’s teacher Mr Martin only has
91 Facebook Friends
In its simplest form, what is the ratio of
Mr Martin’s friends to John’s friends?
273
Friends 91
Friends
Ratio Mr Martin February 2014

24. Key words/ Literacy Skills:
We are learning about:
Ratio
We are learning to:
Use ratio notation, reduce a ratio to its simplest form and divide a quantity into two parts in a given ratio
Success criteria:
Can reduce a ratio to its simplest form (Level 5)
Able to divide a quantity into two or more parts in a given ratio (Level 6)
Maths 17/09/2018
Key words/ Literacy Skills:
Highest Common Factor
Real world problems – Sharing money

25. How did it go? I understood all or most of the lesson
I understood bits of the lesson but not all of it
I am a bit stuck with this and need some more practise

26. Questions?
Ratio Mr Martin February 2014

27. Additional Examples Follow

28. Simplifying Ratios Some more examples: 3 : 12 = 9 : 27 : 90 =
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Simplifying Ratios
Some more examples:
3 : 12 =
9 : 27 : 90 =
5 : 10 : 15 : 25 =
12 : 36 =
81 : 9 =
42 : 28 : 14 =
Answers:
1 : 4
1 : 3 : 10
1 : 2 : 3 : 5
1 : 3
9 : 1
3 : 2 : 1
Ratio Mr Martin February 2014

29. Simplifying Ratios Some more examples: 36 : 12 = 81 : 27 : 9 =
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Simplifying Ratios
Some more examples:
36 : 12 =
81 : 27 : 9 =
8 : 16 : 32 : 40 =
11 : 44 =
6 : 18 =
55 : 33 : 22 =
Answers:
3 : 1
9 : 3 : 1
1 : 2 : 4 : 5
1 : 4
1 : 3
5 : 3 : 2
Ratio Mr Martin February 2014

30. Dividing by a ratio Some more examples:
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Dividing by a ratio
Some more examples:
1. Divide a jar of 20 sweets into the ratio 3:1 =
2. Split a packet of 22 biscuits into the ratio = 3 : 3 : 5
3. Divide 16 into the ratio 2 : 2 : 4 =
Answers:
15 : 5
6 : 6 : 10
4 : 4 : 8
Ratio Mr Martin February 2014

31. Dividing by a ratio Some more examples:
Learning Objectives
To be able to simplify ratios
To be able to divide an amount by a given ratio
Dividing by a ratio
Some more examples:
4. Divide a jar of 32 sweets into the ratio 3:1 =
5. Split a packet of 26 biscuits into the ratio = 3 : 5 : 5
6. Divide 18 into the ratio 2 : 3 : 4 =
Answers:
24 : 8
6 : 10 : 10
4 : 6 : 8
Ratio Mr Martin February 2014