Hold up one chunky magnet only. Do not start testing yet. Take three or four quick ideas from the class. Keep the tone playful: every guess is welcome.

Before the lesson: gather the chunky magnets and mixed object trays; check every magnet is large and chunky (no small or loose magnets); pre-test every tray object yourself so you know which ones pull; print one Investigation Journal page per child; clear small table spaces for groups of three or four.

Safety: magnets stay away from mouths; teacher models holding the magnet by the sides. Children sit while testing. Small tray items (large paperclips, larger coins) stay on the table and are handled one at a time under adult watch.

Board stays to that one short line only. Say the three ideas live while you hold the magnet, a paperclip and a wooden peg — do not put definition blocks on the IWB.

Worked cycle to model live (one object only):

• I wonder if the magnet will pull this metal paperclip.
• I guess yes, because it looks shiny and metal.
• I test by bringing the magnet slowly toward the paperclip (do not snatch).
• I noticed the paperclip stuck to the magnet. Did you see that jump? It moved before I even touched it — that is the magnet pulling.
• I think my guess matched — the magnet did pull it.

Then hold up a wooden peg and ask the class to guess with thumbs up (will pull) or thumbs down (will not). Do not reveal the answer yet — that is for the explore step.

Transition into groups: after the peg thumbs vote, send children to tables in groups of three or four. One chunky magnet and one mixed tray per group. Point to the yes and no spaces already marked on each table.

Misconception to head off: children may think the magnet pulls everything, or only heavy things. Keep the rule simple: some things are pulled, some are not. We find out by testing. Do not teach a full metal rule today; this lesson is the first hands-on guess-then-test introduction.

Who helps us: scientists make a good guess before they test, just like we are doing today.

Before this step

Set one tray per group of three or four with the same mixed objects. Give each group one chunky magnet. Mark two clear spaces on the table (or two small trays) as yes, it pulls and no, it does not so the table labels match the board order. Pre-test every item on the trays yourself so surprises are planned, not accidental.

Transition

Children move from the whole-class model (step 2) to their table groups when you give the cue after the peg thumbs vote. One magnet per group of three or four keeps turns short enough that every child can guess-then-test several objects in about 12 minutes.

How to run it

• Children work in short turns: one child guesses aloud, tests, then places the object.
• Watch that the guess comes before the magnet touches the object. Point to the board list if needed: guess → test → sort.
• Circulate and ask: What do you notice? Did your guess match?
• If a group races, slow them: one object at a time.

Suggested objects on each tray

Large paperclip (teacher-watch; stays on the table), metal spoon (pre-test: some stick, some barely do or not at all), larger coin such as a 50c or €1 (teacher-watch; stays on the table), large safe key if pre-checked, wooden peg, plastic brick, crayon, rubber, fabric scrap, aluminium foil ball (often does not pull strongly). Include at least two surprises. Never present the spoon as a guaranteed yes. Avoid tiny loose bits; listed small metal items are allowed only while children sit, test one object at a time, and keep items on the table away from mouths.

Safety

Chunky magnets only. Magnets never near mouths. Sit down while testing. Small metal tray items stay on the table under adult watch — not in pockets or near faces. If a magnet is mouthed, remove it and wash hands; replace with a clean magnet.

Differentiation: less confident children point and use thumbs only; an adult or peer can model the sentence "I guess… then I test…" without sorting for them. Ready children can say a short why ("I think metal"). Fast finishers re-test one surprised object and tell a partner whether the guess matched.

Hand out now: give each child their Investigation Journal page (printed before the lesson). Hold one up and show the class the two drawing spaces before they begin: one for something pulled, one for something not pulled. Say clearly that two drawings are enough; a surprise is only an optional extra mark or circle, not a third required picture.

This is the in-lesson paper recording beat — not homework. Children draw; emergent labels are welcome if a child is ready (for example a simple mark for "guessed" and "really").

What good looks like: one object the magnet pulled and one it did not. An optional circle or mark if something surprised them.

Observation prompts while they draw:

• Which things stuck to the magnet?
• Which things stayed still?
• Was any guess different from what really happened?

Do not ask children to write long sentences. Drawing is the record at this age.

Whole-class oral talk only. No typing. Revoice from what the class actually sorted on their tables — do not script a fixed list of "yes" metals:

• Name real yes-pile objects children offer (for example the paperclip if groups saw it stick).
• Name real no-pile objects (wood, plastic, fabric, crayon, foil if that is what they found).
• If a spoon (or coin) stayed still in some groups, treat that as useful data: "Our spoon stayed still — interesting!" rather than correcting children toward a metal rule.
• A surprise is useful — it helps us learn.

Keep it gentle: do not turn this into a rule about all metal or all heavy things. At Senior Infants the aim is notice, guess, test, and compare guess with result. A later lesson can look more closely at patterns.

Who helps us: scientists guess carefully, then test to find out. We practised that skill today.