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21st century skills activity · IGCSE 0625 · 1.2 Motion

Gradient and area: running Pairs Check and a Gallery Walk

A step-by-step guide to running both structures, followed by the problem set, the gallery task and a full answer key. The aim is that they can be run faithfully by any teacher, including a cover teacher.

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What they are, and why they work

Solve and coach, then show and review

Pairs Check works inside a group of four, split into two pairs. In each pair, one partner solves a problem aloud (the doer) while the other coaches and checks (the coach); then they swap. After every two problems the two pairs compare answers. A Gallery Walk then has each group display one worked solution on the wall, while the class circulates to review and leave feedback.

A pair solves and coaches and swaps, the two pairs check as a four, then groups display posters for a gallery walk.
Pairs Check, check as a four, then the Gallery Walk

They pass the PIES test:

Positive interdependence

The coach is responsible for the doer's success, and the gallery depends on every group's poster.

Individual accountability

Each learner solves while being coached, and may be asked in review.

Equal participation

Partners alternate doer and coach, and every group displays.

Simultaneous interaction

All pairs work, and then all groups walk, at once.

Before the lesson

Three things to prepare

Running the structures

About 24 minutes, in two phases

Pairs Check · about 14 minutes
Set roles1 min

In each pair, decide who is the doer and who is the coach for Problem 1.

Solve and coach2 to 3 min each

The doer works the problem aloud, drawing the large triangle or splitting the area; the coach watches, prompts with questions, and checks the answer and the unit.

Swap

Change roles for the next problem, so each partner both solves and coaches.

Check as a four~1 min, every two

The two pairs compare answers. If they agree, move on; if not, they reconcile before continuing.

Coaching stems for the coach

"will you use the gradient or the area?" "show me the large triangle" "what is the unit?" "how will you split that area?" "I agree because ..." or "check that again, because ..."
Gallery Walk · about 10 minutes
Make the poster4 min

Each group writes a clear worked solution to its assigned problem on chart paper, showing the graph, the triangle or the split, and the calculation with units.

Walk and give feedback4 min

Groups rotate clockwise; at each poster they leave one star (a strength) and one question (something to clarify) on sticky notes.

Return and read2 min

Groups return to their own poster, read the feedback, and agree one improvement.

The teacher's role during the activity

During Pairs Check, circulate and make sure the coach is coaching, not taking over the pen, and listen for the key decision: gradient for an acceleration, area for a distance. During the Gallery Walk, read the sticky notes and choose one or two points to discuss with the whole class.

Troubleshooting and differentiation

When the room does not behave like the plan

The coach solves instead of coaching: remind them their job is to question and check, not to answer.

A pair races ahead without explaining: ask the doer to talk through the next step aloud.

A poster is unclear: that is exactly what the gallery questions are for; use them in the review.

Uneven group: a three works as a pair plus a coach who rotates each problem.

Problem set (Pairs Check)

Take turns: the doer solves aloud, the coach checks

Give a unit with every answer.

Problem 1 · A solves

A cyclist speeds up from rest to 12 m/s in 6 s. Find the acceleration.

Problem 2 · B solves

A car slows from 30 m/s to 18 m/s in 4 s. Find the deceleration.

✓ Check as a four: compare your answers to Problems 1 and 2.
Problem 3 · A solves

A runner moves at a constant 8 m/s for 15 s. Use the area to find the distance travelled.

Problem 4 · B solves

A speed-time graph shows a rise from rest to 20 m/s in 5 s, then a constant 20 m/s for 10 s. Find the total distance travelled.

✓ Check as a four: compare your answers to Problems 3 and 4.
Problem 5 · A solves

A train speeds up from 10 m/s to 34 m/s in 8 s. Find the acceleration.

Problem 6 · B solves

A speed-time graph shows a rise from rest to 15 m/s in 3 s, a constant 15 m/s for 7 s, then a fall to rest in 5 s. Find the total distance travelled.

✓ Check as a four: compare your answers to Problems 5 and 6.

Gallery task

Your group will be given one problem. On the chart paper, produce a clear model solution: sketch the speed-time graph, show the large triangle or the way you split the area, and write the calculation with units. Then walk the gallery and leave a star and a question on each poster.

Answer key

Acceleration is a gradient; distance is an area

ProblemWorked answer
Problem 1a = Δv ÷ Δt = 12 ÷ 6 = 2 m/s²
Problem 2a = (18 − 30) ÷ 4 = −3 m/s², so the deceleration is 3 m/s²
Problem 3distance = area = 8 × 15 = 120 m
Problem 4triangle ½ × 5 × 20 = 50 m; rectangle 10 × 20 = 200 m; total = 250 m
Problem 5a = (34 − 10) ÷ 8 = 24 ÷ 8 = 3 m/s²
Problem 6½ × 3 × 15 = 22.5 m; 7 × 15 = 105 m; ½ × 5 × 15 = 37.5 m; total = 165 m
Original work by the TheLucidSTEM team. Designed for the lesson on this site; no past paper material is reproduced.
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