How to use the bar method to model and solve problems

• The bar model method is a great way to visualise tricky mathematical concepts and solve problems.

• They are a quick and easy way to represent a situation in a word problem.

• Bar modelling can be used to solve problems involving sales and money.

How do we use this method?

Example

42 cakes are sold between 3 different people. Each person buys a different amount of cakes.

• Maya buys the least amount
• Ali buys twice as many as Maya
• Sam buys four times more than Maya

Question: How many cakes does each person buy?

Solution

1. The total sales was 42. So draw a bar and label it with 42.

2. Maya is identified first as she sold the fewest cakes. As we do not know how much Maya sold, we let her sales equal 1 section.

3. Ali sold double Maya so his sales are equal to 2 sections.

4. Sam sold four times as many as Maya so his sales are equal to 4 sections.

5. In total there are 7 sections. 1 for Maya, 2 for Ali and 4 for Sam.

6. Each section is equal. Therefore 1 section equals 42 ÷ 7 = 6.

Who buys what?

Maya: 6
Ali: 12
Sam: 24

Total = 42 cakes

Where next?

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