Why Paper Towel Capillary Walk works

Think of Paper Towel Capillary Walk as one small problem with several decisions and a clear starting point: place shallow colored water in two cups with an empty cup between them. Use paper towel strips between colored water cups to observe capillary movement over time. What happens there should matter when the child later needs to fold paper towel strips so each bridges from a filled cup into the empty cup.

Set up — Place shallow colored water in two cups with an empty cup between…

Prepare paper, cups, water, and household items before the child is asked to place shallow colored water in two cups with an empty cup between them. Use the result of having the child place shallow colored water in two cups with an empty cup between them as the setup for the move into fold paper towel strips so each bridges from a filled cup into the empty cup. Use household-safe materials and keep the setup stable, supervised, and easy to clean up while that starting condition is being established.

Step 2 — Fold paper towel strips so each bridges from a filled cup into…

Keep the pace slow while the child tries to fold paper towel strips so each bridges from a filled cup into the empty cup. If the effect is hard to see, simplify that action before continuing with the instruction to observe where water first appears in the towel.

Step 3 — Observe where water first appears in the towel

Treat the attempt to observe where water first appears in the towel as a checkpoint between the earlier step to fold paper towel strips so each bridges from a filled cup into the empty cup and the coming step to wait and record how far the color travels. A perfect answer is not required.

Step 4 — Wait and record how far the color travels

After completing the instruction to wait and record how far the color travels, pause and ask what changed from the earlier step where they had to observe where water first appears in the towel. Use that answer to decide whether they are ready to compare both sides as water reaches the center cup.

Step 5 — Compare both sides as water reaches the center cup

Keep the adult prompt brief while the child tries to compare both sides as water reaches the center cup. If needed, return to the earlier step to wait and record how far the color travels before asking them to compare both sides as water reaches the center cup.

What to notice before Compare both sides as water reaches the center…

Keep adult commentary light while the child works toward wait and record how far the color travels. Their own response should show what changes when one condition changes and what stays the same before the activity finishes with the request to compare both sides as water reaches the center cup.

Make Observe where water first appears in the… easier or harder

For younger or less confident players, run one clear comparison with obvious conditions before the step to observe where water first appears in the towel. If the child asks for more, repeat the test, measure more carefully, or change one variable only and then return to the final request to compare both sides as water reaches the center cup.

Finish after Compare both sides as water reaches the center…

Finish after the child manages to compare both sides as water reaches the center cup and can connect that result with the earlier request to fold paper towel strips so each bridges from a filled cup into the empty cup. After that final step, browse the activity search or create a related variation with the activity generator.