Ratio

Ratio

Class Discussion

Learning Objectives:

• Students will be able to construct the ratio based on the data then convert it to the simplest form.

• Students will be able to construct the “Part-to-Part” and “Part-to-Whole” ratios from the data given.

Open Ended

Tell me what you know about ratio.

Multiple Choice

Ratios can be shown in different ways, except:

• Use the “:” to separate the values

• Write it like a fraction

• Use the “;” to separate the values

• Use the word “to”

Rules for comparing quantities:

• The units of measurement must be the same.

• The answer does not state the units of measurement.

• The ratio does not give the actual numbers.

• The ratio must always be written in its simplest form.

Open Ended

Look at the following ratio:

5 kg : 10 g

What's wrong with the ratio above?

Equivalent ratio

The trick with ratios is to always multiply or divide the numbers by the same value.

Multiple Select

Which are the equivalent ratios of 4 : 6?

• 1 : 3

• 2 : 3

• 8 : 12

• 18 : 12

• 20 : 30

Multiple Choice

Read the following description about "Make Some Chocolate Crispies".

To make these chocolate crispies I used:

- 20 grams of chocolate

- 15 grams of cornflakes

Calculate the ratio of chocolate to cornflakes.

• 15 : 20

• 3 : 4

• 4 : 3

• 20 : 15

Multiple Choice

Read the following description about "Make Some Chocolate Crispies".

To make these chocolate crispies I used:

- 20 grams of chocolate

- 15 grams of cornflakes

Work out the amount of ingredients to make 21 cakes.

• 21 grams of chocolate

  21 grams of cornflakes

• 420 grams of chocolate

  315 grams of cornflakes

• 4 grams of chocolate

  3 grams of cornflakes

Part-to-Part and Part-to-Whole Ratios

• A ratio compare one part to another part.

• A ratio can also show a part compared to the whole lot.

Multiple Choice

Look at the picture. What is the ratio of strawberries to total fruit?

• 4 : 3

• 3 : 4

• 7 : 4

• 4 : 7

Post-class activity

Please join the live battle session to review our knowledge about ratio.