Direct proportion

Last updated on Apr 2, 2026

Scaffolded direct proportion interactive worksheet

Direct proportion is a concept where two quantities increase or decrease at the same rate. It’s useful in situations like scaling recipes, converting measurements, or calculating travel times. Understanding direct proportion helps you solve real-world problems where one quantity directly affects another. Jump to the questions

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Question

y is directly proportional to m

y = when m =

Find the equation for y and m

Step 1 - describe the relationship using the correct symbol

y ∝ m

Step 2 - replace the symbol with the constant of proportionality, k

y = m

Step 3 - substitute the values from the question into the equation

= k

Step 4 - rearrange the equation to isolate k

÷ = k

Step 5 - determine the value of k

k =

Step 6 - write the final equation linking y and m

Find y when m =

Step 1 - restate the equation

Step 2 - substitute the value you know

y = ×

Step 3 - determine the final value of y

y =

Find m when y =

Step 1 - restate the equation

Step 2 - substitute the value you know

= × m

Step 3 - rearrange the equation to isolate m

÷ = m

Step 4 - determine the value of m

m =