Rocket marks a starting line with tape. "My wheel goes 2 steps in one turn," he says.
"So how far in three turns?"
He starts counting on his fingers, then stops.
Raven smiles. "What do you notice? Is every turn the same?"
Nova hovers over the line. "If each turn is the same, add the same amount each time," she says.
Each turn of a wheel goes the same distance.
That is a pattern we can use.
Two turns go twice as far as one turn.
Three turns go three times as far.
To predict, multiply the distance around by the number of turns.
| Turns (made-up wheel, 2 meters per turn) | Distance |
|---|---|
| 1 | 2 meters |
| 2 | 4 meters |
| 3 | 6 meters |
| 4 | ? |
A museum scientist shared another real example.
His wheel was 1.5 meters around.
His gears turned the wheel twice for each pedal turn.
So one pedal turn moved the bike 3 meters.
| What | Distance |
|---|---|
| My prediction for 3 turns | |
| What I measured |
Wonderful predicting! Tomorrow we compare big wheels and small wheels.