Animals including Humans

Year 4Lesson 5

LI: To carry out a fair test.

Input

• Why is it important to keep your teeth healthy?• How do you keep our teeth healthy?

Tooth structure

Tooth structure

The tooth is like an egg:• The shell is like the enamel-

protecting the insides of the egg. • The white of the egg represents the

dentin• The yolk signifies the pulp.

Experiment

We are going to be carrying out an experiment that tests how acid in drinks can damage our teeth and what toothpaste does to protect our teeth.

Experiment • We are going to put a hardboiled egg into different drinks

(water, Coca Cola, orange juice, milk, blackcurrant squash).

• Each group will get 1 liquid each to test. • Put another egg (this time covered in toothpaste) into

another beaker with the same liquid in. • The liquids will be left for a week (in a fridge).

Fair test

What does this mean?How can we make our experiment

fair?Why is it important to make our test

fair?

Activity

1. Set up the experiment2. Make sure you keep everything

the same!

Plenary

What does the experiment show?

What has happened to the eggs?What does this tell us about

brushing our teeth?