Learners will investigate how light is used (optical devices) and…

Your Senses: How Does Your Body Know? Grade 4

Map the most sensitive spots on your skin, find the blind spot in each eye, lose the flavour of a jelly bean by pinching your nose, and build an owl ear. Four lessons on how senses gather information and the brain makes sense of it.

• Where is your skin most sensitive? 45–60 min

  Students use a bent paper clip to touch the skin with one point or two, and find the smallest gap they can feel as two on the fingertip, palm, back of the hand and forearm. Then they explain why fingertips are built for reading the world.

• Why do you have two eyes? 45–60 min

  Students try to touch a pen cap to a pen tip ten times with one eye covered and ten times with both eyes open, then make a dot vanish into their own blind spot. They explain what two eyes give the brain that one eye can't.

• Can your nose change what you taste? 45–60 min

  With eyes closed and noses pinched, students try to name the flavour of a jelly bean and tell a cube of apple from a cube of potato. Then they let go of their noses and explain why most of what we call taste is really smell.

• How do animals sense what we can't? 60 min

  Students read about whiskers, echolocation and owl ears, build a paper cone 'owl ear' and test whether it helps them find where a sound comes from. Then they define a problem and invent a sensor or tool inspired by an animal.