Wednesday
Wednesday: Numbers Lab: Measure the Course
The crew stands at the end of the driveway with the tape measure. "Our practice course," Raven says. "Four straight sections."
Rocket runs the tape out. "3.25 meters." He writes it down. "Next section, 4.6 meters."
"Centimeters to meters," Raven reminds him. "What do you notice about 460 centimeters and 4.6 meters?"
"Same length, the point just moves two places," Rocket says.
Nova hovers above the tape, keeping it straight. "Measure twice," she says. "Write once."
Four sections later Raven adds them up. "12.5 meters, one lap. Four laps is one practice run."
"And eight lanes," Rocket says. "How much tape for all of them?" Nova hums. "That is your lab."
Your mission
Measure a short course at home in meters to the hundredth. Add the sections, multiply by laps, and divide into equal parts.
Centimeters become meters when the point moves two places left: 325 centimeters is 3.25 meters.
- A tape measure or a meter stick. A ruler works for short sections.
- Masking tape or chalk to mark the ends of each section.
- A flat space: a hallway, a yard or a sidewalk away from the road.
- Your Numbers Notebook and a pencil.
Walk the course; there is no need to run while measuring. Wear shoes outdoors.
A metal tape measure snaps back fast. Let it rewind slowly, and keep fingers clear of the edge.
- Mark a course with three or four straight sections. Tape or chalk each corner.
- Measure each section twice. Write each length in meters with two decimal places.
- Add the sections with the decimal points lined up. That total is one lap.
- Multiply the lap by 4 to find a practice run of four laps.
- Divide the lap length by 5 to find five equal rest stops along it.
The crew's measurements
| Section | Length (meters) |
|---|---|
| 1 | 3.25 |
| 2 | 4.6 |
| 3 | 2.75 |
| 4 | 1.9 |
| One lap | 12.5 |
Raven's log: 3.25 + 4.60 + 2.75 + 1.90 = 12.5 meters for one lap.
Four laps: 12.5 × 4 = 50 meters. Five rest stops: 12.5 ÷ 5 = 2.5 meters apart.
- Read the question.
- Tap your answer.
| What the lab shows | True or false? |
|---|---|
| 460 centimeters is the same length as 4.6 meters. | ? |
| Adding 4.6 to 3.25 means lining up the 6 under the 5. | ? |
| 12.5 × 4 = 50 | ? |
| Measuring twice helps catch a slipped reading. | ? |
Careful measuring. Tomorrow the crew packs kits and finds what two numbers have in common.