Build a Sundial

Your child sets up a simple sundial outside, marks where its shadow falls at different times through the day, and works out how the shadow tells the time.

How to do it

1. Push a straight stick upright into the ground, or stand a pencil in a lump of clay on a paper plate, in a sunny spot that stays sunny.
2. At a known time, have your child mark where the shadow points and write the time next to the mark.
3. Come back every hour or two through the day and add a new mark and time each visit.
4. At the end of the day, look at the fan of marks together and talk about how the shadow moved and why.
5. The next sunny day, check whether the marks still line up with the clock, and talk about what changed.

What you need

• Stick or pencil
• Marker
• Clock
• Sunny spot

Make it yours

Younger, 6 to 8 years: Mark just three times, such as morning, midday, and afternoon, and skip the next-day check. Older, 10 to 12 years: Mark on the hour, then reason about why the marks are not evenly spaced and how the dial shifts across seasons. Siblings: One child watches the clock while another marks the shadow