# Starter What is a ratio? 1:4 This is Starter What is a ratio? 1:4 This is a ratio. This example tells us that for every 1 part of something we need, we need 4 parts of something else. 1:6 For example, orange squash. For every 1 part of cordial, we need 6 parts water.

2:5 Or pink paint. For every 2 parts of red paint, we need 5 parts of white paint. What is the highest common factor (HCF) of 6 and 8? 12 2

10 4 What is the highest common factor (HCF) of 6 and 8? 12 2 10

4 What is the highest common factor (HCF) of 12 and 16? 48 12 4 24

What is the highest common factor (HCF) of 12 and 16? 48 12 4 24 What is the highest common factor (HCF) of 10 and 25?

5 10 50 2.5 What is the highest common factor (HCF) of 10 and 25? 5

10 50 2.5 What is the highest common factor (HCF) of 24 and 36? 6 12

8 24 What is the highest common factor (HCF) of 24 and 36? 6 12 8

24 To simplify or cancel down ratios, we need to divide by the highest common factor (HCF) of both parts. Simplify: 16 : 20 Whats the highest common

factor of 16 and 20? 4 So divide both numbers by 4 Simplify: 16 : 20 4 4

4:5 Simplify: 6 : 27 Whats the highest common factor of 6 and 27? 3

So divide both numbers by 3 Simplify: 6 : 27 3 3 2:9 Show me a ratio which simplifies to

2:7 What is wrong: To simplify the ratio 32:48 keep dividing both sides by 2 until you cant do it any more True / Never / Sometimes: To simplify the ratios keep dividing both sides by 2 until you cant do it any more What is the same / different: 4:5 and 4:500p 2:3, 34:51 and 3:2 Convince me that 19:95 is

equivalent to 1:5 Pair Task What is the hidden message? I am Batman But shhhh dont tell anyone! Simplify the following: 1) 3 : 6 2) 10 : 15 3) 9 : 12 4) 5 : 10 5) 12 : 6 6) 25 : 10 7) 12 : 16 8) 6 : 30 Leave all ratio answers in their simplest form: 1) This month there were 14 sunny days and 16 wet days. Find

the ratio of sunny days to wet days. 2) In a bag of sweets, 10 are yellow and 15 blue. Find the ratio of yellow sweets to blue sweets. 3) A coach has room for 28 sitting and 16 standing passengers Find the ratio of sitting to standing passengers. 4) In a class there are 12 girls and 18 boys. Find the ratio of girls to boys in the class. Simplify the following: 1) 6 : 15 : 21 2) 8 : 16 : 32 4) 9 : 18 : 45 5) 16 : 32 : 56

3) 9 : 12 :21 6) 36 : 48 : 72 Answers 1) 1 : 2 5) 2 : 1 2) 2 : 3 6) 5 : 2 3) 3 : 4 7) 3 : 4

4) 1 : 2 8) 1 : 5 1) 7 : 8 2) 2 : 3 3) 7 : 4 4) 2 : 3 1) 2 : 5 : 7 4) 1 : 2 : 5

2) 1 : 2 : 4 5) 2 : 4 : 7 3) 3 : 4 : 7 6) 3 : 4 : 6 Starter Standard: Challenging: 56 7 = 8

272 8 = 34 64 8 = 8 48 3 144 12= 12 114 6 = 19 42 6 = 7

105 5 = 21 88 8 = 11 333 9 = 37 = 16 20 is divided between Ann and Jim in the ratio 3 : 2 How much money does each get? 3 + 2 = 5 parts 4

4 4 4 4 Ann Jim

12 8 20 5 = 4 70 is divided between Joe and Kate in the ratio 3 : 4 How much money does each get? 3 + 4 = 7 parts 10 10

10 10 10 10 Joe Kate

30 40 70 7 = 10 10 60 in the ratio 5 : 1 Answer 50 : 10 True

Unsur e False 72 cm in the ratio 7 : 5 Answer 49 cm : 35 cm True Unsur e

False 34 kg in the ratio 4 : 3 Answer 15 kg : 20 kg True Unsur e False Answers

1. 6 : 18 2. 240ml : 560ml 3. 16 : 40 sweets 7. 9L : 9L : 6L 8. 56 : 8 : 32 sheep 9. Dr Barnados: 80 RSPCA: 60 4. 32 : 40 10. Mr Allen: 60 5. 30 : 54 pens Mr Broome: 150

Mr Collins: 210 6. 50 : 20 : 50 Starter Fill in the gaps. 1:2=:6 3 : 4 = 12 : 16 : 12 = : 6 :8=7:4

5 : = 25 : 40 8 : 12 = 1 : Starter Fill in the gaps. 1:2=3:6 16 : 12 = 8 : 6 5 : 8 = 25 : 40 3 : 4 = 12 : 16 14 : 8 = 7 : 4 8 : 12 = 1 : 1.5

On a farm, the ratio of pigs to cows is 2 : 3. The ratio of cows to sheep is 5 : 7. What is the ratio of pigs to cows to sheep? pigs cows LCM of 3 and 5 is 15 10 cows

sheep 15 21 10 : 15 : 21 LCM of 4 and 7 is 28 A pet shop sells mice, rats and gerbils. The ratio of mice

to rats is 4 : 3 and the ratio of mice to gerbils is 7 : 4. If there are 32 gerbils in stock at present, how many rats are there? mice rats mice 28 28 : 21 : 16 gerbils 16 21

56 : 42 : 32 42 rats Answers 1. 2. 3. 4. 5. 6. 7. 8.

12 : 15 : 18 6 : 15 : 20 9 : 21 : 28 10 sheep 30 bottles of rose 42 forks 64 years old 420 children Plenary What did you learn today? What did you find tricky? What

can we do next time? Starter Calculate the following: 1) 3 x 2 =6 2) 4 x 1.5 =6 3) 6 x 2.5

= 15 4) 4 x 1.25 =5 5) 7 x 2.5 = 17.5 Recipes Restaurants have to make money.

If too much food is made, it will be thrown away. If not enough food is made, the customers wont come again. In either case, the restaurant will fail. So, calculating the right amounts is essential! Recipes Here are the ingredients needed to make ratatouille for 4

people. To find out how much of each well need to make it for 6 people, we need to use ratio. Ratatouille Serves 4 2 large aubergines 4 small

courgettes 2 yellow peppers 4 large tomatoes 5 tbsp olive oil 1 onion 3 garlic cloves Recipes The ratio of people in the recipe and people we have is 4 : 6 We can simplify this by dividing both amounts by 2 we get 2 : 3 To calculate the scale factor, simplify so the

ratio is in the form 1 : n The ratio is now 1 : 1.5 so the scale factor is 1.5 Recipes For 6 people: Ratatouille Serves 4 2 large aubergines 4 small courgettes 2 yellow peppers

4 large tomatoes 5 tbsp olive oil 1 onion 3 garlic cloves x 1.5 2 x 1.5 = 3 large aubergines 4 x 1.5 = 6 small courgettes 2 x 1.5 = 3 yellow peppers

4 x 1.5 = 6 large tomatoes 5 x 1.5 = 7 tbsp olive oil 1 x 1.5 = 1 onions 3 x 1.5 = 4 garlic cloves Recipes Your turn! Shortbread fingers Makes 20

120g butter 50g caster sugar 170g plain flour x 2.5 300g 125g 425g How much of each ingredient will be needed to make 50 fingers? Hint 20 : 50

Extension: Pancake day! Answers 12 tomatoes 2 potatoes 2 onions 4 tbsp olive oil 4 pints vegetable stock 2 carrots 8 slices of bread 1 tsp olive oil 1 large onions 3 cloves of garlic

375g minced beef 300g chopped tomatoes 4 mushrooms 300g spaghetti 275g butter 275g sugar 5 medium eggs 2 tsp vanilla essence 275g flour 250g jam 1200g prawns 12 tsp mayonnaise

12 tsp tomato sauce 12 lettuce leaves 15 roast potatoes 5 carrots 2 cans of peas 10 slices of beef 5 Yorkshire puddings 3 watermelons 7 bunches of grapes 14 bananas 21 oranges

28 apples 2800g strawberries Plenary Rosa prepares the ingredients for pizzas. She uses cheese, topping and dough in the ratio 2:3:5 Rose uses 70 grams of dough. Work out the number of grams of cheese and the number of grams of topping Rosa uses. Cheese ......................... g Topping ....................... g (Total 3 marks)

Starter Match the questions and answers. Answers Which is the Best Buy? 1.2kg for 3.89 700g for 2.14 700g

for 2.14 1.2kg for 3.89 What is the price per gram? 1200g = 389p 1200 1200

1g = 0.324p 700g = 214p 700 700 1g = 0.305p This is less money per gram, so it is the best buy Which is the Best Buy?

TRESCO Supermarket Sells cheese on its deli counter for 1.88 per 160g WEIGHTROSE Supermarket sells cheese on its deli counter for 13.55 per kg 13.5 5 per kg 1.88 per 160g

What is the price per gram? 160g = 188p 160 160 1g = 1.175p 1000g = 1355p 1000 1000

1g = 1.355p This is less money per gram, so it is the best buy Order these starting with the best value for money. D A can of coke that costs 60p

A Buy one can for 70p, get one free B Buy 2 can for 60p each, get one free C Two cans of coke for 1 Order these starting with the best value for

money. A 5 books for 10 D One book for 3 B A 4.80 book has 50% off

C Buy one book for 5, get one free Extension: Best buys investigation Answers Carrots 1.2 kg bag @ 1.00 Pork sausages Packs of 10 @ 4 for 12.00 Andrex toilet roll 4 pack, 2 for 3.50 Bacon 300g pack, 2 for 4 Diet Coke 2L bottles, 3 for 4.50

Deodorant Gillette 200ml, 3 for 2 (2.33 each) Radox handwash 500ml, 3 for 2, 1.90 each Group Activity Your budget is 50. You must spend as little as possible, purchasing everything required on the list, for the best value. How well do you know your currencies? 1. What currency is

used in Japan? 2. What currency is used in France? 3. What currency is used in Ireland? 4. What currency is used in India? 5. What currency is used in Australia? 6. What currency is used in the USA?

Exchange Rates What are exchange rates? The rate at which one currency may be converted into another. Exchange Rates When will I use this? Any time you go abroad where the currency is not Pounds Sterling. Exchange Rates The exchange rate is 1 to \$1.70. I need to convert my 56 into US

Dollars. 56 x 1.7 = \$95.20 X 1.70 1 = \$1.70 1.70 Exchange Rates On my return journey I have \$12 left. What is this worth in Pounds ()? \$12 1.7 = 7.06

X 1.70 1 = \$1.70 1.70 Extension: Complete the round the world activities. Think/pair/share Use the table to calculate the following exchange rates: a)

b) c) d) e) Pounds Sterling to Japanese Yen Japanese Yen to US Dollars US Dollars to Australian Dollars Australian Dollars to Euros Euros to Pounds Sterling Extension: What are the reverse rates?

Group Activity You are travelling the world! But how much did you spend? Plenary A student bought a pair of sunglasses in the USA. He paid \$35.50 In England, an identical pair of sunglasses costs 26.99 The exchange rate is 1 = \$1.42 In which country were the sunglasses

cheaper, and by how much? Show all your working. (Total 3 marks)