Humanities Ratio Revision

Ratios and Ratio Tables

I can use a RATIO TABLE to organise equivalent ratios to solve problems.

What do you need to know about Ratios?

• They are a comparison of 2 quantities.

• We are focusing on Part to Part ratios

• We can switch between ratios and fractions

• ORDER MATTERS! 3 : 1 is not the same as 1 : 3

Multiple Choice

What is the ratio of stars to red circles in this image?

• 4 : 11

• 4 : 7

• 7 : 4

• 11 : 4

​Ratio tables can be used to organise information and find missing values.

Multiple Choice

A school sells raffle tickets to raise money. In the table, x represents the number of tickets sold and y represents the money they earn. How much money would they earn if they sold 100 tickets?

• $175

• $225

• $400

• $500

Multiple Choice

The table shows how fast Amy can walk on the treadmill. Based on this table, how many feet could Amy walk in 21 seconds?

• 48 feet

• 60 feet

• 72 feet

• 84 feet

Fill in the Blanks

The table shows the number of pages Blaine can read in his book. How many pages can he read in 20 minutes?

Multiple Choice

The table shows the number of pages Blaine can read in his book. How many pages can he read in 42 minutes?

• 14

• 39

• 45

• 126

Multiple Choice

Fully simplify the ratio...

40 : 60

• 2:3

• 4:6

• 10:15

• 3:2

Multiple Choice

Simplify to lowest terms

• 6
• 2/8
• 1/6
•  2/12

Multiple Choice

A class has 30 students. 18 are boys. What is the ratio of boys to girls? (you must simplify)

• 12:18

• 3:2

• 30:18

• 18:7

Multiple Choice

What is a Ratio?

• Is a comparison of two quantities 
• To multiply two fractions 
• A number over another number
• Two decimals that can be multiplied

Multiple Select

Choose the two ratios are equivalent.

• 300:10

• 1:3

• 30:1

• 6:5

What do we use Ratios for?

• Recipes (100ml flour to 1 part salt)

• Building (4 parts sand to 1 part cement)

• Maps (1cm to 1km/mile)

• Plans (scale drawings)

• Mixing drinks (1 part cordial to 6 parts water)

• Infection Rates (1 person may infect 1.5 other people, etc)

Sharing Ratios (for example, how do we split £24 in the ratio 3 : 1)?

• Add the Ratio Numbers up (3:1 3+1 = 4)

• Divide £24 by 4 = £6

• Multiply each part of the ratio by £6

• 3 x 6 = 18, and 1 x 6 = 6

• Check the amounts add up correctly (£18 + £6 = £24)

Multiple Choice

Bob and Ben win £100 and agree to split the winnings in the ratio 2 : 3 How much does Ben get?

• £30

• £40

• £50

• £60

Multiple Choice

Kate and Gill's meal comes to £35 and they agree to split in the ratio 1 : 4 How much does Gill pay?

• £7

• £14

• £21

• £28

Open Ended

A baker makes 1 white sandwich for every 4 brown sandwiches. Today he has mad 350 sandwiches; how many were white?

Proportion

You can use Proportion to scale up and down

Direct Proportion

• If an amount is directly proportional to another, it means that as one amount increases, the other amount increases at the same rate

• To calculate Direct Proportion, use a ratio table to scale up or down.

Multiple Choice

A photocopier can copy 16 pages per minute.

How many pages can copied in 7.5 minutes ?

• 100 pages

• 120 pages

• 160 pages

• 175 pages

Fill in the Blanks

If 4 coaches can carry 168 passengers,

how many passengers can 3 coaches carry?

Multiple Choice

Every 30 seconds, you can text 35 words. How many words can you type in 5 mins?

• 1200

• 350

• 1000

• 1,800

Inverse Proportion

(the opposite of Direct Proportion)

• If an amount is inversely proportional to another, it means that as one amount increases, the other amount decreases at the same rate

• To calculate Inverse Proportion, find the value of ONE UNIT (by multiplying) and then DIVIDE using that value

Multiple Choice

3 workers build a wall in 12 hours. How long would it have taken for 6 equally productive workers?

• 6

• 12

• 36

• 48

Multiple Select

12 men can dig a pond in 8 days. How many men can dig it in 6 days?

• 20

• 15

• 16

• 24

Multiple Choice

The number of hours to paint a house varies inversely with the number of painters working. A 2400-square foot house can be painted in 27 hours by 6 painters. How many painters would need to work in order to paint the house in 18 hours?

• 8 painters

• 10 painters

• 9 painters

• 11 painters

Hopefully this lesson has helped you to revise for your assessment on Tuesday. Remember to use century and ALO to revise over the weekend.

​

Well done