Reach for the Star

Proportion problems and repair

Pearson Edexcel GCSE Mathematics 1MA1 · Foundation and Higher · L016 · Review v0.9

Your learning journey

Select and justify a proportion method. Diagnose whether the given amount is a total, a share or a difference.

Work without a calculator except for an invited check. Keyboard - means the same as −. Attempt before opening a scaffold or intentional practice explanation.

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Ready.

Connect & Check

Corresponding: quantities in matching roles. Total: sum of all shares. Difference: larger share minus smaller share. Direct proportion: constant ratio of corresponding quantities.

Intentional practice feedback after your attempt

15 and 25.

Eight equal parts.

Intentional practice feedback after your attempt

300 g.

Multiply by 6/4.

Intentional practice feedback after your attempt

£5/kg.

Double the quantity and cost.

Share

In pairs, predict the first step and compare your reasons before reading the worked solution: D1 Model: total 35 shared 2:5 gives parts of 5, hence 10 and 25. Now share 56 in ratio 3:4.

Present

For A:B=2:3, the whole contains five equal parts but the difference contains one part. The number of parts depends on what the given amount describes. In direct proportion, multiplying one quantity by a factor multiplies the other by the same factor.

Label the ratio parts and the meaning of the known amount. Find one part or one unit; scale to the target. Check the original ratio and the stated total or difference.

Optional scaffold

Divide by the sum of the terms.

Intentional practice feedback after your attempt

24 and 32.

Seven parts; one part 8.

Optional scaffold

Match 15 to three parts.

Intentional practice feedback after your attempt

35.

One part 5; seven parts 35.

Optional scaffold

Divide by 5−3.

Intentional practice feedback after your attempt

A=21; B=35.

Two parts equal 14.

Optional scaffold

Find one serving first.

Intentional practice feedback after your attempt

600 g.

75 g per serving.

Apply

Optional scaffold

Label total, share or difference.

Intentional practice feedback after your attempt

16; 20; 16.

Divide by 5, 3 and 1 respectively to find one part.

Intentional practice feedback after your attempt

£40 and £32; £60 and £48.

The second given amount is one part.

Optional scaffold

Convert litres to millilitres.

Intentional practice feedback after your attempt

Need 300 ml syrup and 1200 ml water; short by 50 ml.

1500÷5=300 ml per part.

Optional check after A3: 1500÷5=300 and 300+1200=1500. The sum check is necessary but also check syrup:water=1:4.

Apply and extend

Optional scaffold

Scale both ratios to the same B value.

Intentional practice feedback after your attempt

No. Match B to 12: A:B:C=8:12:15, so A:C=8:15.

The two original B parts have different sizes.

Intentional practice feedback after your attempt

No in general. Flour:sugar 2:1 becomes 4:1 rather than 4:2.

All corresponding ingredients must scale together.

Access, Scaffold, Core and Stretch support the same goal. Stretch deepens reasoning for either qualification tier.

Recall & Review

Retrieval without notes

Six retrieval points. Enter a number, decimal, fraction such as 3/2, or mixed number such as 1 1/2. Equivalent numeric values are accepted. Unsupported notation goes to teacher review. For rounding, also communicate the requested accuracy in written work; numerical scoring cannot judge significant trailing zeros.







Not checked.

Independent exit evidence

P1–P2: five minutes, no notes, 4 marks. Your teacher reviews working and explanations. Full assessment solutions are not embedded.

Recall & Review and prepare

An algebraic expression records a calculation with a letter representing a number. For x=4, 3x+2 means 3×4+2, while 3(x+2) means 3×(4+2).

Retrieve F1 again in one week. Bring your working and one question.

Your progress summary

Completion records attempts, not mastery. Retrieval points describe the latest checked attempt. Your teacher reviews P1–P2 separately and checks retained understanding after a delay.

Restore a backup

Original Reach for the Star. Not an official or endorsed Pearson resource. Separate teacher package contains assessment solutions. Local saving is browser-dependent; no account or dashboard service is included.

Optional extension activities

Stretch

Check after attempting

4×15/6=10 hours.

Deep challenge

Check after attempting

The inverse model assumes equal productivity and no coordination limits; those assumptions may fail.

Recall & Review: feedback and extension integration

Lesson L016: Proportion problems and repair

Objective: Select and justify a proportion method. Diagnose whether the given amount is a total, a share or a difference.

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.

What Went Well (WWW)

I selected a suitable representation or multiplier and kept the reference amount clear.

Even Better If (EBI)

I will state the whole/part, show each operation and check that the size of my answer is reasonable.

Stretch and deep challenge

Stretch: Four workers complete a job in 15 hours at constant rate. How long would six workers take?

Deep challenge: Explain why doubling workers may fail to halve time in a real job.