L068 · Allow 10–15 minutes for learners ready to move on. Answers are available after an attempt.
A car uses 18 litres over 240 km. Express fuel use in litres per 100 km.
18/240×100=7.5 L per 100 km.
A distance is fixed. If speed increases by 25%, what happens to journey time?
Time factor=1/1.25=0.8, so time falls by 20%.
Lesson L068: Rates pathway and repair
Objective: Select a proportion or rate method and explain assumptions.
60-minute structure: 0-7 Connect & Check; 7-14 Share; 14-25 Present/model; 25-44 Apply route choice/practice; 44-52 independent exam-style check; 52-60 Recall & Review, WWW/EBI and next step.
I used my working and assessment evidence to identify the exact mathematical step that was secure and the specific misconception that needs attention.
I will correct one precise step, explain why the correction works and complete a fresh delayed question without the original scaffold.
Stretch: A car uses 18 litres over 240 km. Express fuel use in litres per 100 km.
Deep challenge: A distance is fixed. If speed increases by 25%, what happens to journey time?