Cambridge Primary (1-6). Stage 6. Science. Learner's Book - Unit 1: The human body - Question 36

Investigate breathing

You will need: a balloon

1 Put your hands on your rib cage.
2 Breathe in. What do you feel?
3 Now breathe out. What do you feel?
4 Breathe in again. Hold the balloon to your mouth and breathe out. What happens to the balloon? What does this show you?