New
New
Year 7

Ratio language and notation

I can understand and use the language and notation of ratio and use a ratio table to represent a multiplicative relationship and connect this to other known representations.

New
New
Year 7

Ratio language and notation

I can understand and use the language and notation of ratio and use a ratio table to represent a multiplicative relationship and connect this to other known representations.

Lesson details

Key learning points

  1. A ratio table is a representation of a multiplicative relationship.
  2. A ratio has two numbers, connected by a multiplicative relationship.
  3. These two numbers together represent a whole.
  4. The total of the two numbers tell us how many equal parts the whole is split into.
  5. Ratio notation is a more efficient way to express the relationship between the numbers.

Common misconception

To find one part, some students simply divide the amount by the sum of the 'parts' of the ratio.

Strengthen understanding of which amount represents which part of the ratio. Matching problems to bar models helps.

Keywords

  • Proportionality - Proportionality means when variables are in proportion if they have a constant multiplicative relationship.

  • Ratio - A ratio shows the relative sizes of 2 or more values and allows you to compare a part with another part in a whole.

Get pupils be creative and write as many ratios they can see in class (in its simplest form) e.g. brown hair : blonde hair, etc. They can extend this by writing their own ratios using their favourite sports, family member ages, recipes, etc.
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.
Why do we use symbols and notation in mathematics?
Correct answer: They are easier to read and understand.
Correct answer: They are concise and take up less space.
They are pretty.
Correct answer: They can be used to represent complex concepts.
Correct answer: It allows mathematical ideas to be communicated more effectively than words.
Q2.
Which of the following is equivalent to "For every 3 circles, there are 4 squares."?
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
Q3.
A number and its reciprocal will always have a product of .
Correct Answer: 1, one
Q4.
For every 5 ml of orange concentrate, use 100 ml of water. What is the multiplier for orange to water?
Correct Answer: 20, twenty
Q5.
For every 5 ml of orange concentrate, use 100 ml of water. To make 420 ml of squash, how much concentrate do you need?
Correct Answer: 20, 20ml, 20 ml, twenty
Q6.
For every 2 cups of flour, there are 3 cups of water. If there are 13.5 cups of water, how many cups of flour are there?
Correct Answer: 9, nine, 9 cups of flour, 9 cups

6 Questions

Q1.
Match the equivalent ratios.
Correct Answer:3 : 4,6 : 8

6 : 8

Correct Answer:5 : 4,25 : 20

25 : 20

Correct Answer:6 : 5,12 : 10

12 : 10

Correct Answer:3 : 2,9 : 6

9 : 6

Correct Answer:2 : 3,12 : 18

12 : 18

Q2.
There are __________ equivalent ratios.
only 1000
Correct answer: an infinite number of
a finite number of
a million
Q3.
Match the ratio tables to the correct simplified ratio notation.
An image in a quiz
Correct Answer:a),2 : 3

2 : 3

Correct Answer:b),1 : 2

1 : 2

Correct Answer:c),1 : 1

1 : 1

Correct Answer:d) ,5 : 9

5 : 9

Correct Answer:e),15 : 5

15 : 5

Q4.
In a bag there are only triangles and squares. The ratio of triangles to squares is 4 : 1. There are 40 shapes in total. Who correctly worked out the number of squares?
Alex "40 triangles, so there are 10 squares because of the ratio is 4:1"
Laura "160 triangles, so there are 40 squares because of the ratio is 4:1"
Correct answer: Sofia "32 triangles, so there are 8 squares because of the ratio is 4:1"
Andeep "30 triangles, so there are 10 squares because of the ratio is 4:1"
Jun "24 triangles, so there are 16 squares because of the ratio is 4:1"
Q5.
The chocolates in a box either have red or blue wrappers. The ratio of red to blue is 3 : 4. If the difference between the red and blue chocolates is 5, how many chocolates are in the box?
Correct Answer: 35, thirtyfive, thirty five, thirty-five
Q6.
The chocolates in a box either have red or blue wrappers. The ratio of red to blue is 2 : 1. Andeep eats 3 blue chocolates and now the ratio is 12 : 5. How many blue were originally in the box?
Correct Answer: 18