Capstone Part 1 of 2. Keep the hook light: show the tipping tablet or book and ask the question. Do not hand out the build kit or name variables yet.

If the class has no tablet: use a hardback book or a plastic lunchbox of similar size as the stand-in load for the whole project.

Key questions: Who will use this? What must it never do? What would count as success?

Before this step

Have the tipping demo still visible. Capture agreed phrases on the IWB.

Target user need (guide the class toward this shape)

A stand for our class that holds a tablet (or book) upright on a desk, stays steady when the desk is lightly bumped, and lets pupils put the device in and take it out easily.

Key Concepts

Nature of STEM: real engineers start with the user, not the materials. Naming the need is engineering work, not a warm-up.

Misconception to head off: “The coolest-looking stand is the best.” Beauty is fine; the user need decides success.

Drive the fair-test-planner on the IWB. Target placement:

• Change: base shape (wide base versus narrow base, both built to the same height)
• Measure: how easily it tips (class default: count gentle fingertip nudges until it tips, stop at 10; use tips / does not tip only as support)
• Keep the same: the load on the stand, how hard we nudge it, the height of the stand

Pupils then complete the option-test section of their Investigation Journal page for their group’s option test. Groups may note tips / does not tip as a simpler measure if needed, but the class default is nudge count to 10, with the same load and the same nudge method.

Worked model (say aloud before groups plan): I wonder which base is steadier. I predict the wide base will tip less easily than the narrow base when both are the same height, because more of it sits on the desk. A wider base gives the stand more room to lean before it topples, like standing with your feet apart instead of together. I will change only the base shape (wide versus narrow), keep the load, the nudge, and the height the same, and count how many gentle fingertip nudges it takes to tip (stop at 10). I think the wide base will win.

If groups want a different option pair (for example three legs versus a solid base), allow it only if they can still change one thing, measure one thing, and keep the rest the same, including matched height. Note the agreed pair on the IWB so step 4 does not overwrite it.

Required prep (do this before the lesson)

Pre-cut matched-height base templates for every group so the 14 minutes stay on testing, not cutting. Each group needs one wide and one narrow template cut from card:

• Shared height: both samples have a short upright face about 5 cm tall (the top edge where the load rests is the same distance from the desk).
• Wide base footprint: about 15 cm across the front by 10 cm deep, with the 5 cm upright face taped or folded along the back edge.
• Narrow base footprint: about 6 cm across the front by 10 cm deep, same 5 cm upright face.
• How the load rests: lean the book or tablet mock-up against the upright face so it sits at a gentle angle, not flat on the card. You are testing how easily that short cradle tips when nudged from the side.
• Assembly in class: groups only fold or tape the pre-cut pieces into the cradle shape, place the load, and run the nudge test. Do not invent freehand bases of different heights.

If a group’s fair pair from step 3 was not wide versus narrow (for example three legs versus solid base), they still use pre-cut pieces cut to the same height rule and change only that one feature.

Setup

Give each group their two pre-cut templates plus tape. Use the same book or tablet mock-up as the load for every trial. Agree the class default nudge: one gentle fingertip push from the same height and force; count nudges until tip, maximum 10.

Procedure

• Assemble base A and base B to the same height from the templates (default: wide and narrow).
• Place the same load leaning against each upright face.
• Apply the agreed nudge; record nudge count to tip (or tips / does not tip as support).
• Repeat once to check the reading.
• Choose the base shape that performed better against the user need.

What to expect: the wider base usually tips less easily. If results are mixed, check that height and load really matched.

Safety: round-tip or supervised scissors only if a small trim is needed; adults make any tough card cuts; keep loads modest so nothing falls toward faces.

All groups are practical at once. Circulate and cold-call fair-test checks across groups: “Was that nudge the same both times? What would make this unfair?”

Display the success criteria and the kit list on the IWB before groups plan (they expand the agreed user need into checkable lines):

• Holds the tablet or book upright on a desk
• Stays steady when the desk is lightly bumped
• Device or book can go in and out easily
• Built only from the flexible build kit provided

Kit on the board (show the physical kit too if you can): cardboard and card; lolly sticks; masking tape (default join); glue sticks optional for paper-to-paper only; string; clean recycled boxes or tubs; scissors.

Prefer tape for speed: PVA or wet glue will not set before the stop clock. Do not offer PVA in this lesson.

This step is plan only. Keep the products light so groups finish in time: one labelled side sketch (base, support, resting place), materials ticked from the board list, success criteria ticked (not rewritten in full). Circulate and check that the winning base idea from the option test is actually used in the sketch. Do not start full builds until the next step.

Differentiation: some groups add a simple lip or stop so the device cannot slide forward; keep the core criteria the same for everyone.