"Every captain gets one square of foil," Raven says.
Rocket grins. "Wide boats, here we come!"
Nova hovers above the water. "I will count every coin."
Whose boat will carry the most cargo?
A boat floats by pushing water out of the way.
Water pushes back up. That is buoyancy.
Wide, flat boats push aside more water.
Same foil, same coins, one change.
◇ FAMILY CARGO BOAT CONTEST
Each captain gets the same size foil square. Fold a boat with no tape. Add coins one at a time, spread out. Count the coins before water comes in. Then fold a new shape and try again.
For a grown-up
Use a shallow tub and stay close the whole time. Cut the foil squares ahead of time. Ask: why do you think your shape carried more?
Safety first
A grown-up stays near the water. Coins never go in mouths.
BUILD DAY CHECK
Read the question.
Tap your answer.
Which boat shape will likely carry more?
CAPTAIN CHECK
Read the question.
Tap your answer.
One captain uses a bigger foil square. Is that fair?