Paint with Numbers

Australian curriculum number (ACMNA173)

This sequence explores ratios through the context of mixing paint. Students recognise that ratios express a multiplicative relationship between two measures and that the numerical values of both quantities need to change by the same factor for the proportion to remain constant (covariation). 

This sequence is for students who have a knowledge of multiplication.

Lesson 1: Mixing Paint

Students mix two batches of pink paint, one batch mixing red and white paint in the ratio 1:2 and the other batch in the ratio 1:5. They explore how to keep the ratio constant when increasing the quantity of red or white paint.

Lesson 2: Adding Parts

Students are posed with the scenario of painting a wall using a mixture of blue and white paint in the ratio of 1:3. They determine if adding an extra tin of each colour changes the ratio.

Lesson 3: Fairer Shares

This task presents the context of combining two equal sized tins containing different shades of green paint. One tin contains a mixture of green and white paint in the ratio of 1:3, the second tin a mixture in the ratio of 1:7. Students determine the resulting ratio of green to white paint when the two tins are combined.


Last updated April 28 2020.