A predict-test-sort investigation in which the child takes a strong child-safe magnet around the home, predicts which objects will be attracted, and sorts them into “Sticks” and “Doesn’t Stick” piles.
- Give the child a large, child-safe magnet — a horseshoe magnet, big bar magnet, or wand magnet. Do not use small neodymium / rare-earth magnets (see Safety).
- Set up a collection tray with 8–12 small household objects of varied materials — a coin (test it!), aluminum foil, a paper clip, a wooden block, a plastic spoon, a piece of fabric, a key, a brass hairpin, a steel screw, a soda can tab, a glass marble, a rubber band.
- For each object, the child predicts first: “Will the magnet stick to it? Why?” Place the object on the Predict-Sticks or Predict-Doesn’t-Stick side of a paper sorting mat.
- The child holds the magnet near (not on) the object and tests. Move the object to the Actual-Sticks or Actual-Doesn’t-Stick column. Were there surprises?
- After all objects are sorted, talk: “What do the Sticks ones have in common? What about the Doesn’t-Stick ones?” Most kids will arrive at some metals stick, others don’t. That’s the real-science finding (the rule is iron / steel / nickel / cobalt — not just “metal”).
Variation: magnet through paper / cardboard / fabric — does the attraction work through a barrier? Try thicker barriers until the magnet “stops working.” Or magnet fishing — paper-clip “fish” with magnet on a string. Or find-the-hidden-magnet — bury a small piece of steel in dry rice and use the magnet to fish it out.
Requirements
- Space: A table; can extend to a magnet hunt around the home
- Surface: Any
- Materials: A large child-safe magnet (horseshoe, bar, or wand — must fail the CPSC small-parts cylinder test), 8–12 small household objects of varied materials, a paper sorting mat with four labeled quadrants (Predict / Actual × Sticks / Doesn't), pencil, optional barrier materials (paper, cardboard, fabric)
- Participants: 1 adult + 1 child
- Supervision: Close — see the critical magnet safety note below
Rationale & Objective
Magnetism is the canonical preschool physical-science topic because the effect is reliable, repeatable, and at child-scale (Worth 2010; Ashbrook NSTA). NGSS K-PS2-1 and the K-PS2 cluster cover forces and motion at this age. The activity is a near-perfect example of the predict → test → classify cycle Gelman & Brenneman describe in PrePS — and the “some metals stick, others don’t” finding produces a productive surprise that rewires the child’s “metal = magnetic” over-generalization. HighScope KDIs Observing, Classifying, Experimenting, Predicting, Drawing conclusions, and Natural and physical world are all hit in a single session.
Progress Indicators
- Early: predicts at random or always says “yes”; loses the magnet to the floor; doesn’t sort after testing
- Developing: predicts based on a single feature (“it’s silver, so it’ll stick”); tests and notices when wrong; sorts with prompting
- Proficient: predicts based on material (“it’s iron, those stick”); sorts independently; spontaneously notices the rule (“the silver paper doesn’t stick but the silver fork does”); explores barriers (“the magnet still works through the paper!”)
- Advanced: distinguishes types of metal (“this is steel, that’s aluminum”); designs follow-up tests (“what if I tape two magnets together — does it stick farther?”); explains the finding to a sibling; remembers and applies the rule weeks later
Safety Notes
- CRITICAL: never use small neodymium / rare-earth magnets with preschoolers. The CPSC reports ~2,400 magnet ingestions per year in U.S. emergency rooms; two or more swallowed magnets attract through intestinal walls causing perforation, sepsis, and death. CPSC 16 CFR Part 1262 (effective 2022) regulates these. Use only large craft, horseshoe, bar, or wand magnets that fail the small-parts cylinder test
- Pinch hazard — strong magnets can snap together suddenly. Hold them apart deliberately
- Magnets erase / damage credit cards, mechanical watches, hard drives, and pacemakers — keep clear of these
- Skip the test on knives, scissors with sharp tips, and anything sharp
- Skip iron-filings demos at this age (inhalation / eye hazard)
- Wash hands after handling old / unfamiliar metal items (rust, lead-paint risk on antique objects)
Hints
- Playfulness: call it a “Magnet Mission” or “Detective Magnet” — the child wears a paper badge and carries the magnet on a clipboard hunt around the home
- Sustain interest: new room each session — kitchen day, bedroom day, garage day, outdoor day. Keep a tally of “how many sticks were found in each room”
- Common mistake: lecturing about iron and steel before the child tests. The whole point is that the child discovers the rule. Also: lots of “silver-looking” things (foil, aluminum, brass) don’t stick — those are the productive surprises; don’t skip them
- Limited space: a kitchen drawer plus 10 minutes is enough — forks, spoons, coins, a sponge, a rubber band, a piece of foil
- Cross-domain: count items in each pile (numeracy); name colors and materials (vocabulary); sort by a second property after the magnet test (classification); test the same item twice to confirm (repeatability)
- Progression: clearly different materials (steel screw vs. wood block) → mixed materials (battery: steel jacket + plastic ends) → barrier tests (paper, cardboard, fabric, water) → distance test (how far away does the attraction stop?) → field-line drawing on paper around the magnet → make a magnet by stroking a needle on a strong magnet
Sources
- Worth, K. (2010). "Science in Early Childhood Classrooms: Content and Process," ECRP/SEED publication
- Worth, K. & Grollman, S. (2003). *Worms, Shadows, and Whirlpools*. Heinemann / NAEYC
- Ashbrook, P. (NSTA *Science and Children* — "The Early Years: Exploring Magnetism")
- Gelman, R., Brenneman, K. et al. (2009). *Preschool Pathways to Science (PrePS)*. Brookes Publishing
- NGSS K-PS2-1 and K-PS2 cluster (forces and motion)
- HighScope KDIs — Observing, Classifying, Experimenting, Predicting, Drawing conclusions, Natural and physical world
- Head Start ELOF — Scientific Reasoning (P-SCI 1, 3, 5)
- Teaching Strategies GOLD Objective 24 (scientific inquiry), Objective 26 (physical properties)
- CPSC Magnet Safety Standard (16 CFR Part 1262, 2022) — magnet ingestion injury data
- NAEYC (2013). *Spotlight on Young Children: Exploring Science*