Field-test pack

Original STEM activities for 4 year olds.

Five small experiments to try with a 4 year old at home. Each one is written so a parent can set it up quickly, say one clear prompt, and watch what actually keeps the child engaged.

How to use this page: Pick one activity, spend 5-10 minutes, and write down what your child actually did. These are field-test drafts, not polished claims yet.
AgeBuilt for 4 year olds; adjust down for younger siblings.
PrepUse household materials already in the room.
GoalGet one prediction, one test, and one redesign.
Stop ruleStop while it is still fun. Five good minutes counts.

1 · ramps and force

Ramp Detective

A toy-car test where the child investigates which surface makes a car roll farthest.

Setup

  • Books or couch cushion for a low ramp
  • Flat cardboard or tray
  • Toy car
  • Towel, foil, paper, or a placemat for surface changes

Kid steps

  1. Roll the car on the plain ramp.
  2. Add one surface to the ramp.
  3. Guess: faster, slower, or stuck?
  4. Roll again and compare.
Say this Which road will make the car go farthest: smooth, soft, or shiny?
Watch for Does your child change one thing at a time, or do they turn it into free car play? Both are useful notes.
Make it easier Use only two surfaces: plain cardboard and towel.
Make it harder Add tape marks and ask which roll stopped closest to the door.
Testing note

Record: minutes engaged, favorite surface, whether the child made a prediction, and what confused them.

2 · engineering

Bridge Rescue

A bridge-building challenge where a toy has to cross a gap without falling into the river.

Setup

  • Two books
  • Paper, index cards, cardboard strip, or straws
  • Small toy animal or car
  • Blue towel or paper as the river

Kid steps

  1. Put the books apart.
  2. Choose bridge material.
  3. Help the toy cross.
  4. Fold, stack, or change the bridge.
Say this The toy needs to cross the river. What bridge should we build first?
Watch for Does the story help engagement? Does the child test gently or smash-test immediately?
Make it easier Start with a narrow gap and a flat cardboard bridge.
Make it harder Ask the bridge to hold two toys or cross a wider river.
Testing note

Record: material chosen first, whether folding paper helped, and the exact phrase your child used when the bridge failed.

3 · light and shapes

Shadow Builder

A flashlight-and-block activity where the child changes shadow size and shape by moving objects.

Setup

  • Flashlight
  • Blocks, cups, or toy animals
  • Wall, door, or plain sheet
  • Painter tape for a shadow target, optional

Kid steps

  1. Pick one object.
  2. Shine the light at the wall.
  3. Move the object closer.
  4. Make a tiny shadow and a giant shadow.
Say this Can you make the same toy look tiny, then huge, without changing the toy?
Watch for Does the child understand moving closer/farther, or do they need your hand-over-hand demo?
Make it easier Use one block and only ask for big shadow, small shadow.
Make it harder Build a block tower and trace where its shadow lands.
Testing note

Record: whether lights had to be dimmed, if the child avoided shining in eyes, and which shadow change got the biggest reaction.

4 · structure and stability

Windproof Tower

A tower challenge where the child redesigns the base after gentle wind knocks it down.

Setup

  • Blocks, cups, magnetic tiles, or DUPLO
  • Paper plate or folded paper fan
  • Optional tape line for the tower spot

Kid steps

  1. Build a tower.
  2. Fan it gently.
  3. Notice what fell.
  4. Build it wider and test again.
Say this The wind is coming. How can we make this tower stay standing?
Watch for Does your child naturally widen the base, lower the tower, or just rebuild the same tower?
Make it easier Build with cups; they fall dramatically but do not hurt.
Make it harder Add a rule: it must be taller than your hand and survive three gentle fans.
Testing note

Record: material used, tower height, number of redesigns, and whether failure felt funny or frustrating.

5 · water and buoyancy

Tiny Boat Cargo Test

A sink-or-float challenge where the child builds a small foil boat and tests how much cargo it can carry.

Setup

  • Small sheet of foil
  • Shallow tray of water
  • Large cargo pieces like DUPLO bricks or big buttons
  • Towel under the tray

Kid steps

  1. Shape a foil boat.
  2. Float it in the tray.
  3. Add one cargo piece.
  4. Change the boat and try again.
Say this Can your boat carry one passenger? What should we change before adding another?
Watch for Does your child pinch the sides higher, flatten the bottom, or only keep adding cargo until it sinks?
Make it easier You shape the first boat and let the child add cargo.
Make it harder Compare a flat boat, a bowl boat, and a long boat.
Testing note

Record: cargo count before sinking, whether redesign happened, and how messy the water setup felt.

What to report back after testing

  • Which activity got the fastest yes?
  • Which one lasted the longest?
  • Where did instructions break down?
  • What phrase did your child repeat or invent?
  • Which setup felt annoying enough that you would not repeat it?