New
New
Year 10
Higher

Checking and securing understanding of sharing in a ratio

I can use a ratio fluently in the context of sharing.

New
New
Year 10
Higher

Checking and securing understanding of sharing in a ratio

I can use a ratio fluently in the context of sharing.

Lesson details

Key learning points

  1. Bar models can help to represent a situation.
  2. It is important that the parts are equal, otherwise the ratio is not represented correctly.
  3. A ratio table can also be used to help show the multiplicative relationship.
  4. Both representations help to expose the structure.
  5. Once the structure is understood, the representations will not be needed.

Common misconception

Procedural understanding of sharing in a ratio where pupils add the parts, divide the amount by this and then multiply by each part without considering the information in the question.

In the lesson encourage pupils to look for keywords in the question which indicate if the amount given is the total, one part or the difference. The use of a bar model to display the information can also be used to help pupils.

Keywords

  • Ratio - A ratio shows the relative sizes of two or more values and allows you to compare a part with another part in a whole

Mini white boards can be useful to sketch bar models.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Select the options that show a ratio written in its simplest form.
0.25
Correct answer: 3 : 4
12 : 15
Correct answer: 18 : 13
18 : 15
Q2.
Write the single multiplier which connects the two numbers shown. Give your answer as a decimal.
An image in a quiz
Correct Answer: 0.6
Q3.
Match up the equivalent ratios.
Correct Answer:2 : 5,40 : 100

40 : 100

Correct Answer:4 : 1,20 : 5

20 : 5

Correct Answer:6 : 7,30 : 35

30 : 35

Correct Answer:15 : 6,100 : 40

100 : 40

Correct Answer:2 : 3,30 : 45

30 : 45

Q4.
Find the correct value to complete the ratio table.
An image in a quiz
Correct Answer: 25
Q5.
Match each of the letters to the number they represent in this ratio table.
An image in a quiz
Correct Answer:a,4

4

Correct Answer:b,$$\frac{3}{5}$$

$$\frac{3}{5}$$

Correct Answer:c,$$\frac{1}{4}$$

$$\frac{1}{4}$$

Correct Answer:d,$$\frac{5}{3}$$

$$\frac{5}{3}$$

Q6.
Alex and Sam share £24 in the ratio 3 : 5 How much does Alex get?
Correct Answer: £9, 9

6 Questions

Q1.
Select the ratios that are equivalent to 3 : 8.
8 : 3
Correct answer: 6 : 16
Correct answer: 7.5 : 20
4 : 9
30 : 80 : 10
Q2.
Alex and Sofia share some money in the ratio 3 : 5. They share £360 in total. How much does Alex get?
Correct answer: £135
£225
£45
£120
Q3.
Alex and Sofia share some money in the ratio 3 : 5. Alex gets £360. How much does Sofia get?
Correct answer: £600
£135
£225
£216
Q4.
Alex and Sofia share some money in the ratio 3 : 5. Sofia gets £360. How much did they share in total?
Correct answer: £576
£960
£360
£225
£135
Q5.
Alex and Sofia share some money in the ratio 3 : 5. Sofia gets £360 more than Alex. How much did Alex get?
Correct answer: £540
£135
£216
£900
Q6.
Izzy, Laura and Jun share some money in the ratio of 3 : 2 : 7. Jun gets £60 more than Izzy. How much does Laura receive?
Correct answer: £30
£10
£120
£24