Reach for the Star

Scale and proportion

Pearson Edexcel GCSE Mathematics 1MA1 · Foundation and Higher · L014 · Review v0.9

Your learning journey

Use constant multiplicative relationships for recipes and length scales, with consistent units and checks.

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

Direct proportion: corresponding quantities have a constant ratio. Scale factor: multiplier from one length to another. Scale 1:n: one unit on the drawing represents n of the same units in reality. Unit rate: amount for one unit.

Intentional practice feedback after your attempt

2:3; 20 and 30.

Equivalent ratios preserve the relationship.

Intentional practice feedback after your attempt

300 cm; 1.5 kg.

100 cm per metre; 1000 g per kilogram.

Intentional practice feedback after your attempt

450.

300÷2×3.

Share

In pairs, predict the first step and compare your reasons before reading the worked solution: D1 Model: 4 people need 300 g, so 6 need 300×6/4=450 g. Same recipe: 8 people need 600 g. Find the amount for 10 people.

Present

If a recipe for 4 people needs 300 g, the same recipe for 6 needs 300×(6/4)=450 g. Both quantities scale together. On a 1:500 plan, 1 cm represents 500 cm=5 m. A labelled scale is a relationship; printed diagram size can change when a page is resized.

State corresponding quantities and units. Use a unit rate or one scale factor across a direct-proportion table. For scale lengths, multiply drawing by n to get real length, or divide real length by n for drawing length, after converting to matching units.

Optional scaffold

Find the amount for one person.

Intentional practice feedback after your attempt

750 g.

Scale 8 to 10 by 5/4, or use 75 g per person.

Optional scaffold

Check the quotient stays constant.

Intentional practice feedback after your attempt

25.

Multiply the first value by 2.5.

Optional scaffold

Convert centimetres to metres last.

Intentional practice feedback after your attempt

35 m.

7×500=3500 cm.

Optional scaffold

Convert 15 m to 1500 cm first.

Intentional practice feedback after your attempt

3 cm.

1500÷500=3.

Apply

Optional scaffold

One centimetre represents five metres.

Intentional practice feedback after your attempt

5 m; 15 m; 30 m.

All lengths scale by the same factor.

Intentional practice feedback after your attempt

360 g; 4 cm.

40 g per person; 800 cm÷200.

Optional scaffold

Convert each dimension separately.

Intentional practice feedback after your attempt

30 m; 20 m; perimeter 100 m.

2×(30+20)=100; lengths scale before perimeter.

Optional check after A3: 6×500÷100=30 m; 4×500÷100=20 m; 2×(30+20)=100 m. Drawings are schematic and not for measuring. Print resizing does not change the labelled lengths.

Apply and extend

Intentional practice feedback after your attempt

Only A. A costs £0 at 0 km and doubles when distance doubles; B has a fixed £4 charge.

A constant rate plus a fixed charge is not direct proportion.

Optional scaffold

A 2 cm line becomes 4 cm for the same 10 m.

Intentional practice feedback after your attempt

1:250. Each printed centimetre now represents half the previous real distance.

The original written scale is no longer correct for ruler measurements.

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

A unit rate is an amount for one unit. Compare like units, such as price per notebook or per kilogram. In L015, the lower unit price will help identify the better buy when the product and conditions are comparable.

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

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Optional extension activities

Stretch

Check after attempting

200,000 cm=2 km.

Deep challenge

Check after attempting

Area factor 1.5²=2.25, since both dimensions scale.

Recall & Review: feedback and extension integration

Lesson L014: Scale and proportion

Objective: Use constant multiplicative relationships for recipes and length scales, with consistent units and checks.

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: A scale drawing is 1:25,000. What actual distance does 8 cm represent?

Deep challenge: Similar shapes have length factor 1.5. Compare their area factor and explain.