Level 4: Rate of change

Change and motion · level 4 of 8 · rough age 11-12 (a guide for parents; anyone can start anywhere)

In level 3 you found rates by sharing a total over a time. In this level the rate becomes a precise tool: change in output divided by change in input, with units, for any table or graph. You learn why a constant rate always draws a straight line, read distance as the area under a speed-time graph, tell steady change from growth that feeds on itself, and convert speeds so that a Mars rover, a cheetah and a beam of light can be compared fairly.

Lesson	You will be able to
Rate of change from a table	Find a rate of change between any two rows, with units, and tell it apart from "total ÷ input"
Constant rate means a straight line	Explain why a constant rate gives a straight line, and write and use the rule "start value + rate × input"
Speed-time graphs	Read speeding up, slowing down and steady speed from a speed-time graph, and find distance as an area
Linear and non-linear change	Tell linear from non-linear change in tables and graphs, with savings and the area of a square
Reading rates from graphs	Find the fastest part of a journey and the biggest change in an hour, using rise ÷ run and the axis scales
How fast are things?	Convert between m/s and km/h, and compare speeds from a growing hair to light

Previous: Level 3: rates and graphs that tell stories · Next: Level 5: slope as a rate · Change and motion topic page