What lifts the big balloon?

A big bag of air sits on the grass. What could ever lift it?

2

A little flame makes warm air. All around is cool air.

warm air cool air
3

Here is the big balloon, with a flame right under it…

4

Tap to turn the flame on… and off!

Tap the picture — light the warm flame.

5

We light the warm flame under the balloon. Will it FLOAT UP or STAY DOWN?

Tap your guess!