Water Clock Estimation
How can water help you mark the time? You'll find out when you use a water clock estimation. It's not a clock like the one that hangs in your kitchen, of course, but it can help you to "tell time" when you check on the water level of this special kind of clock.
Sound complicated? It's not. Here's how to begin making your time-telling tool, a water clock:
What You'll Need:
- Paper cup
- Straight pin
- Cylinder-shaped jar
- Permanent marker
- Digital clock
Step 1: To make the clock, pierce a hole in the bottom of the paper cup with a straight pin.
Step 2: Set the cup in the jar so it rests in the rim -- the bottom of the cup should not touch the bottom of the jar.
Step 3: With a digital clock or a watch with a second hand nearby, fill the cup with water.
Step 4: Using a permanent marker, record the water level reached at 1-minute intervals on the outside of the jar. Mark off each minute for 15 minutes.
Step 5: Then empty the cup and the jar, and get ready to use the water clock for estimation challenges.
How many minutes does it take you to brush your teeth? How long does it take to make a peanut butter and jelly sandwich or to do 25 jumping jacks?
Make an estimate, fill the glass with water, do the task, and test your estimate.
You can also make another clock for tracking time for longer periods. Use a larger jar, and this time, mark the water level reached at 15-minute intervals. You might want to use a kitchen timer to remind you when to record the 15-minute intervals.
How long would you estimate it would take to "slime" a toy soldier? Learn all about it on the next page of fun science projects for kids.