Reach for the Star

Signed numbers

Calculate, explain and check

Pearson Edexcel GCSE Mathematics 1MA1 · Foundation and Higher · L001 · Review v0.9

Your learning journey

Work without a calculator, except for the optional check. Type a minus with your keyboard (-); it means the same as −. Try each question before opening a prompt or practice explanation. Read your explanation aloud if that helps.

Answers save in this browser when storage is available. They do not sync between devices. Export a backup before closing, moving or renaming this file. Avoid entering personal information.

Ready.

Connect & Check

Integer: a whole number including negative whole numbers and zero. Ascending: least to greatest. Opposite: same distance from zero, other side.

Optional scaffold

Mark −5 and −1 on a number line.

Intentional practice feedback after your attempt

−5, −1, 0, 2

Ascending means least to greatest. A number farther left is smaller.

Optional scaffold

What added to 3 gives 8?

Intentional practice feedback after your attempt

5; 5 + 3 = 8

Subtraction and addition undo one another.

Optional scaffold

Imagine temperatures of −2°C and −7°C.

Intentional practice feedback after your attempt

−2, because it is farther right on the number line.

A larger digit does not make a negative number greater.

Share

In pairs, predict the first step and compare your reasons before reading the worked solution: D1 Worked example: −3 + 5 = 2. Start at −3 and move 5 units right. Check: 2 − 5 = −3. Now work out −4 + 6 and explain the move.

Present

A sign belongs to a number; an operation tells you what to do. Adding a positive moves right. Adding a negative moves left. Subtraction adds the opposite: a − b = a + (−b). Adding b back returns a, so the inverse operation checks the result.

Adding five to negative threeAn equally spaced number line from negative five to five. A rightward arrow goes from negative three to two, a change of positive five.−5−4−3−2−1012345+5

Start −3, move five units right, finish 2. Check 2 − 5 = −3.

Optional scaffold

Move 4 units to zero, then 2 more.

Intentional practice feedback after your attempt

2; start at −4, move 6 units right.

Adding a positive number moves right. Cross zero carefully.

Optional scaffold

First reach zero, then move 3 more units.

Intentional practice feedback after your attempt

−3; 5; left; −3 + 5 = 2.

Adding a negative number moves left by its distance from zero.

Optional scaffold

Rewrite subtraction as adding the opposite.

Intentional practice feedback after your attempt

−8; −8 + 5 = −3.

Subtracting a positive number moves left.

Optional scaffold

What number plus −5 equals −3?

Intentional practice feedback after your attempt

5; 2

Subtracting a negative adds its opposite. The inverse check explains why.

Apply

Optional scaffold

Read “subtract negative seven” aloud before rewriting.

Intentional practice feedback after your attempt

(a) 11 (b) −3 (c) −3 (d) 11

The operation and the sign of the second number both matter.

Optional scaffold

Use your own number line if needed, then try again without it.

Intentional practice feedback after your attempt

(a) 3 (b) −15 (c) 3; e.g. 3 + (−9) = −6.

Only one feature varies at a time. Explain why (a) and (c) agree.

Optional scaffold

Find the temperature after the rise before applying the fall.

Intentional practice feedback after your attempt

−4 + 9 − 3 = 2°C. Check: 2 + 3 − 9 = −4.

An increase is a positive change; a decrease is a negative change.

Optional calculator check for A3: estimate the sign first. Use your calculator’s negative-number key (−), +/− or neg for the starting −4, then + 9 − 3. Models differ; ask your teacher to demonstrate. The display should show 2. Include °C in the contextual answer.

Apply and extend

Optional scaffold

Try subtracting a negative number.

Intentional practice feedback after your attempt

For example, 1 − (−2) = 3, and 3 > 1. One counterexample disproves “always”.

A counterexample must contradict the stated claim, not just give another calculation.

Optional scaffold

Think about positive, zero and negative values of b.

Intentional practice feedback after your attempt

Exactly when b < 0. Subtracting a negative adds a positive amount. b = 0 leaves a unchanged; b > 0 decreases it.

Use a general argument and consider zero. This extension is available to either tier.

Stretch is available to either tier. Support needs and qualification tier are separate. A counterexample must contradict the claim.

Recall & Review

Retrieval without notes

Enter a number, decimal, simple fraction such as 3/2, or mixed number such as 1 1/2. Equivalent exact values are accepted. If your notation is not recognised, it is referred for review, not marked wrong. There are 6 retrieval points; these do not include method marks.







Not checked.

Independent exit evidence

P1–P2: five minutes, without notes. Total 4 marks. Your teacher reviews the method and explanation. No assessment solutions are embedded here.

Recall & Review and prepare

Read: 3 × 4 means three groups of four, giving 12. Division undoes multiplication: 12 ÷ 3 = 4. In 2 + 3 × 4, multiply first to obtain 14. L002 explains multiplication/division of signed numbers and operation priority.

Repeat F1 tomorrow and in one week. Bring one question and your working.

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

−26; for example (−18+27)−35=9−35=−26.

Deep challenge

Check after attempting

False: −8−(−3)=−5, still negative.

Recall & Review: feedback and extension integration

Lesson L001: Signed numbers

Objective: Order integers; signed addition/subtraction; explain and check.

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 an efficient numerical method, showed the key steps clearly and checked the sign, size or accuracy of my answer.

Even Better If (EBI)

I will make the place-value, sign or operation decision explicit and use estimation or an inverse calculation to check a fresh question.

Stretch and deep challenge

Stretch: Calculate −18+27−35 and check by grouping in a second way.

Deep challenge: A learner claims subtracting a negative always gives a positive answer. Test the claim with a counterexample.