1. Riddles
Mr Smith has 4 daughters. Each of his daughters has a brother. How many children does Mr Smith have?
During which month do people sleep the least?
There is an ancient invention, still used in some parts of the world today, that lets people see through walls. What is it called?
What goes up and never comes down?

3. Ratio & Proportion Week 05:
Calculate ratio and proportion, including problems using currency conversion
Understand ratio as a number of parts, simplify and solve for a given number of parts
Solve ratio problems where one number is a multiple of another
Understand direct proportion is the same rate of change
Understand ratio notation written in the form 3:2.
Link fractions, decimals, percentages, ratio and proportion

4. What did we do last week?

5. 12/20
4/10
16/20
£240
1/4
8/10
2/5
12/16
6/11

6. Work out 3/5 of 120
Work out 30% of 250
Write 0.27 as a percentage
Which is larger: 35% or 1/3?
Which is larger: 25% of 200 or 1/12 or 1000?
What does BIDMAS stand for?
Use BIDMAS to solve – 2 x 2

7. Why do we need to convert currency?
Currency Conversion
Why do we need to convert currency?
What is an Exchange Rate?
Are Exchange Rates always the same?

8. Thai Baht
Jamaican Dollar
Canadian Dollar
Indian Rupee
Russian Ruble
Euro

9. £100 x €1.39 = €139 £1 = €1.39 (Euros) What is £100 in Euros?
Convert the following amounts to Euros:
a) £ b) £ c) £210
€291.90
€27.80
€208.50

10. €200 ÷ €1.39 = £143.88 £1 = €1.39 (Euros) What is €200 in Pounds?
Convert the following amounts to Pounds:
a) € b) € c) €325
£35.97
£57.55
£233.81

11. Ratio Ratio is a way of comparing amounts
It shows how much bigger one part is compared to another
Ratio is written 1 : 2
This ratio has 3 parts altogether as = 3. This is important!

12. 250 million users
How many users?

13. 12 million viewers
How many viewers?

14. CD sales
Digital album sales

15. Calculating Ratio Divide each amount into the given ratio
Step 1: Add up the total number of parts:
For example: share 30 in the ratio 1:2
1 + 2 = 3 parts
Step 2: Divide the amount by the total number of parts (this gives you the value of one part):
30 ÷ 3 = 10
10 is the value of 1 share
Step 3: Multiply by each part of the ratio:
10 x 1 = 10
10 x 2 = 20
So, sharing 30 in the ratio 1:2 = 10 : 20

17. £20

18. £350
£??

19. £800
Jim
Jemima
Find the value of Jim and
Jemima’s shares.

20. £??
£280
£??
Find the value of the whole amount
and the missing share.

21. Painting
You have decided to paint your hallway purple. You need 3:2 blue and red paint. If you need 500ml of paint in total to cover the wall, how many ml of blue and red paint will you need?

22. Cement
You decide to cement your patio. The cement mix requires 3 parts cement, 2 parts sand and 1 part water. If you need 250kg of mix, how much cement, water and sand will you need?

23. Ratio
£16 in the ratio 5 : 3 £99 in the ratio 7 : 2 £60 in the ratio 7 : 3 £28 in the ratio 3 : 4 £140 in the ratio 6 : 3 : 1

26. Daniel Freddie George Bobby Cathy Alan Ellie Total
Prague
Zurich
Paris
Milan
Madrid
Berlin
Munich
Prison sentence
The total amount stolen was __________
The robber who made the most money was __________

27. The total amount stolen was €240 million
Daniel
Freddie
George
Bobby
Cathy
Alan
Ellie
Total
Prague 2 6 4 12
Zurich 18
Paris 3 9 21
Milan 8 16 20 80
Madrid 10
Berlin 24
Munich 15 25 5 75 33 23 50 51 37 28
240
Prison sentence 11
72/3
162/3 17
121/3
91/3
The total amount stolen was €240 million
The robber who made the most money was Bobby

28. Proportion
There are 30 children in a class in the ratio 2:1. There are 20 boys. What proportion are boys?
With words:
As a fraction:
20 out of 30 20 30
As a decimal:
As a percentage:
66%

29. Direct Proportion
We can use the ratio of something to multiply or divide a quantity as required, e.g:
3 tins of blue paint : one tin of white
If you need to mix 9 tins of blue paint you will need 3 of white

30. Using Ratio to describe statistics
There are 3 people with green eyes to every 1 person with blue eyes : Direct Proportion: If there are 4 people in a class with blue eyes, then there is likely to be 12 people with green eyes.

31. Exam Question Year 10 and Year 11 students are in assembly:
Year boys : girls Student data
: boys
: students
Work out the total number of girls in the assembly.