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Science Rocks!

Game Timer


your results

Sent in by:
Huston of Williamsburg

Make a game timer that could be more fun than the game!

Materials Needed

  • small soda or water bottles
  • water
  • sand
  • pebbles
  • plastic wrap
  • rubber bands
  • duct tape
  • scissors
  • small paper cups
  • plastic tubing
  • cardboard tubes
  • paperclips
  • stopwatch
  • paper and pencil



  1. Work in teams of two to build a game timer that measures exactly 10 seconds.
  2. Talk about what problem you are trying to solve. Can you think of different solutions? Sketch out your different design ideas so you can compare them more easily.
  3. Decide which design you want to try and begin building using just the materials listed above.
  4. Test your timer against a stopwatch. Does it measure 10 seconds? How close can you get it to 10 seconds?
  5. Does your timer measure the same amount of time each time you try it? What changes could you make to your design to get your timer to be more consistent? Look at the designs of different game timers you have to get ideas. How do they work? How are they different from the one you made and how are they the same?
  6. Redesign your timer and test it to see if you get more consistent results. You can also try using different materials like rice or salt. If you come up with any great designs, send them to ZOOM.

Some of your Results

Briaunna, age 10 of Chicago, IL wrote:
well it was ok and the first one you I had to sruggled but I pass it.

Jasmine, age 8 of Sydney, NS wrote:
When I tried this experiment, I saw that when you tip the bottle upside down, I found out that the piece of paper and the hole inside would let the sand go through and make a sand timer.

Molly, age 13 of Peoria, AZ wrote:
This worked so well. I was an awesome way to time games and made it easy. It was also a lot of fun to put together.

Kerri, age 11 of Calgary, AB wrote:
I used tons of stuff and it actually worked it measured 10 seconds and I could make it to measure 20 seconds to. It was so much fun.

Meagan, age 12 of Little Falls, MN wrote:
It was really hard to do because I ran out of room to do it! In the end I just did a zig zag idea and let the right amount of sand and paper clips go down the course until ten seconds was up.

not yet implemented