Math · MeasurementVISUAL DISCOVERY 08 OF 1,100
Roll a Circle Flat
Builder · about 6 minutes · a little curiosity goes a long way
For grown-ups
Today’s little discovery
One complete roll lays the circular boundary onto a line. Its length is always π times the diameter, so C = πd = 2πr.
Compare several lids and divide each trail by its diameter.
This is a learning model. Try the take-home activity together.Voice settings
Using Heart (en-US).
Your selected voice and opening narration get ready when the page opens with Sound on. The first visit downloads a voice model (about 92 MB), which your browser can cache. No lesson text is sent to a speech service.The sample plays once and does not change the Sound on/off setting.- Wonder
- Guess
- Try it
- Discover
- Celebrate
HERE’S A LITTLE WONDER…
How long is one trip around a circle?
A wheel leaves one colored mark after exactly one full roll.
No rush. Try an idea and see.