Dear Subscriber First Name,

Have you ever wondered why an hour has sixty minutes instead of one hundred?

The answer goes back 5,000 years. The Ancient Sumerians living in Mesopotamia didn’t count in tens like we do now. They had a base-60 number system, which means they counted in sixties. When Sumerians invented time tracking, they split an hour into 60 minutes, and we have kept that same system for thousands of years!

Ancient Babylonians used a sundial to tell the time. A sundial is an object that shows the time based on where the sun’s shadow falls. As the sun’s position in the sky moves during the day, the shadow cast by a part of the sundial will move around the base. Markings on the base indicate the time.

You can make a sundial using this simple method:

How to Make a Paper Plate Sundial

WHAT TO DO

1. Place one of the paper plates face-up and fill with sand (this is to weigh it down so the sundial does not move).

2. Glue the other paper plate upside-down on top of the first paper plate.

3. Pierce the center of the top paper plate and stick the straw in the hole, pushing it down into the sand so it stays vertical. OPTIONAL: Use a compass to angle the straw towards the North. When your sundial is done you can move it and use it somewhere else as long as the straw is angled North.

4. On a sunny day, place the paper plate in a location that gets full sunlight all day. (Do not move it from this spot!) OPTIONAL: If you angled the straw towards the North, you can move it as long as the straw is still pointing North.

5. Using the watch, every hour, use the markers to mark the location of the straw's shadow on the edge of the plate. Label it with the time.

6. When your sundial is finished you can decorate it.

The activity is part of our new Mesopotamian Inventions resource which explores the Mesopotamian inventions of the wheel, writing, maps, the sail, weapons, wine, beer, irrigation, cities and time tracking.