Keep this light. Hold up one everyday object with a clear moving part if you have it to hand (a toy car, a pair of scissors closed and open, a hinge on a cupboard door) and ask pupils to point to the part that moves. Do not hand out build materials yet.

Key questions: Which part moves? What is that movement for (what can you see it do)? Where else have you seen something like this (bike wheels, garden gates, a lunchbox lid)?

STEM eyes: moving parts are all around us in toys, gates, bikes and classroom gadgets. We are going to make one of our own.

Project only the short board text. Anchor job at once with the bin lid or toy car you held up in Getting Started so pupils can point before they choose. Do not teach all three mechanism names as whole-class vocabulary. Use the sketches as picture choices; name the type only for the option each table builds.

Use the table below for your own reference and for answering questions while you circulate.

Option labels for the three picture choices (not whole-class key concepts; name only the one each table builds):

• Lever that lifts: a stiff bar on a fixed point so one end lifts when you push the other (like a seesaw or bin lid). Sketch: card strip on a split pin lifting a rubber.
• Wheel-and-axle cart that rolls: wheels on sticks (axles) so the model can roll. Default is two axles and four wheels so the cart rolls straight. Each wheel may turn with the axle or spin on it. Sketch: card cart with four card-circle wheels.
• Pull-tab that slides: a strip you pull so another piece slides along a slot or tape guides. Sketch: strip sliding a picture out of a card frame.

Misconception to head off: pupils may think the whole model has to move. Stress that one part moves and the rest is the steady frame. Also, a wobbly join is not "more moving"; smooth movement needs a firm join that still allows the part to turn or slide.

Keep the three lift / roll / slide sketches on the board. Tables are pre-assigned (or trays pre-labelled) so choice does not eat build time in the next step.

Before the lesson

• Pre-assign each table one option (Lift, Roll or Slide) and label the tray, or set trays so only that option's kit is obvious. This locks choice in under a minute and protects build time.
• Set out one materials tray per group with pre-cut card rectangles (about A5), paper strips, split pins, tape, pre-cut thick card-circle wheels with centre holes already punched (default wheels), blunt skewers or thin dowels, and round-tip scissors. Add bottle tops only if you already collected and holed them.
• Pre-punch split-pin holes in a few base cards and half-started lever bases (pin already in) so groups are not waiting on one hole punch.
• Pre-cut a few sliding picture pieces and long paper strips for pull-tab groups.
• Build one ready sample of each option (lever, four-wheel cart, pull-tab) the night before or first thing, so every join can be held up and pointed at before release.
• Keep the hole punch for adult top-ups only; most holes should already be ready.
• If adult help is tight, run only Lift and Slide tables; offer Roll only where pre-made wheels and two axles are ready on the tray.

Worked example (you model joins first, about 3 minutes total)

Give every option a comparable join cue before anyone builds. Leave the three board sketches up as well.

• Lever (about 90 seconds, think aloud): I wonder if a card strip on a pin can lift a small rubber. I predict that if the pin is in the middle, a small push on one end will lift the other. Fold or layer a strip for stiffness, push a split pin through the middle into a base card, place a rubber on one end, press the other. I observed: the rubber rose; a floppy strip bends instead of lifting. I think a stiffer strip and a pin that is not too tight will make a smoother lift later.
• Cart (about 45 seconds, hold up the ready sample): Point: card body, two sticks as axles, four wheels (two per stick). Wheels may turn with the stick or spin on it. Job: roll across the table when pushed.
• Pull-tab (about 45 seconds, hold up the ready sample): Point: picture taped to a long strip that slides in a slit or between two tape guides. Job: pull the end so the picture slides out.

Then release tables to build only their assigned option. Circulate; help with pins and sticks. Adults make any leftover tricky holes or cuts.

How to support each option

Lever that lifts: base card + stiff strip + split pin as the pivot + a light load (rubber or paper clip). Job: lift the load when you press the other end.

Cart that rolls (default: two axles, four wheels): card body, two blunt skewers or dowels as axles, four card-circle wheels (or bottle tops) so the cart rolls straight. Job: roll across the table when pushed.

Pull-tab that slides: base card with a straight slit or two tape guides, a sliding picture piece taped to a long paper strip. Job: pull the tab so the picture slides out or across.

Teaching tips

• One moving part is enough. Stop groups from adding motors, multiple levers, or complex stories.
• If a group finishes early, ask them to test whether the part moves the same way every time before the improve step.
• Differentiation: offer a half-started lever base (pin already in) for pupils who need a quicker start; confident groups can add a simple label or a second light load to test the lever, still with only one moving part.

Safety: adult supervision with scissors and pointed skewers; store sharp ends pointing down on the tray; no running with materials.

This is a gentle Stage 2 inquiry, not a fair test. Do not use the words fair test or variables. Keep the focus on "try it, notice, change one thing, try again".

Question for the class: What can we change so our moving part works more smoothly?

What to look for:

• Lever: pin too tight (hard to tip) or strip too floppy (bends). Fix: loosen the pin slightly or double the card.
• Cart: wheels pointing different ways or axle taped too tight. Fix: straighten the two axles, free the wheels so they can turn, check all four line up.
• Pull-tab: path too narrow or tab twisting. Fix: widen the path with tape guides, stiffen the tab.

Ask aloud: What was sticky or wobbly? What one change did you try? Is it smoother now? Fold watchers in by asking the wider class what they would try next if it were their model.

Misconception: pupils may change three things at once and not know what helped. Gently steer them back to one change.

Pupils record on the paper Investigation Journal page. Do not describe a special layout or invent named boxes; the journal page is generated for them. Keep the three stems on the IWB for the whole step so Stage 2 writers are not relying on a single spoken prompt.

Realistic Stage 2 demand: every pupil must draw the model and mark the moving part. Written stems are a goal, not a gate: pupils who draw well but write slowly may point-and-say the stems to you or a partner while you jot a brief note. Aim for at least one stem written where possible.

Circulate and ask pupils to point on their drawing to the moving part so you can check they have not drawn only decoration.

Look-fors: the moving part is visible on the drawing; the pupil can say what happens when they use it (lift, roll or slide); at least one improve idea is named aloud or on the page.