Wednesday
Wednesday: Build Lab, Pouring the Cone
Rocket holds a paper cone over the tray. "Same radius as the can, same height. I checked twice."
"Measure twice, pour once," Raven says. She levels the rice in the cone with a ruler. "Pour."
The rice slides into the can. Rocket peers in. "About a third of the way up. One."
A second cone-ful. "Two thirds." A third cone-ful, and the rice sits level with the rim.
"What do you notice?" Raven asks. "Three cone-fuls, exactly a can," Rocket says. "Just like the rule."
Nova hovers above the tray, her light counting the stray grains. "Do it twice more," she says. "A rule needs repeats."
Rocket is already refilling the cone. Nova hums. "Keep the rice over the tray."
Your mission
Make a paper cone with the same radius and height as a can. Fill it with rice and pour it into the can.
Count how many cone-fuls fill the can. Do three trials. Then compute both volumes and compare.
- An empty can with a smooth rolled rim, or a plastic cup.
- A sheet of paper, tape and scissors for the cone.
- Dry rice or sand, a tray, a ruler and a tape measure.
- Your Blueprint Book and a pencil.
Rice stays over the tray and goes back in its bag. Nothing is eaten. Keep it away from children under three and pets.
Scissors only, with a grown-up nearby. Sweep up stray grains so no one slips.
- Measure across the top of the can and halve it for the radius. Measure the height.
- Roll paper into a cone with the same radius at its mouth and the same height. Tape it and trim the top level with scissors.
- Fill the cone with rice and level it with a ruler. Pour it into the can.
- Repeat until the can is full. Count the cone-fuls and record them.
- Empty the can and do two more trials.
- Compute the can's volume and the cone's volume with 3.14. Divide the first by the second.
The crew's pouring log
These are the crew's own trials at the Blueprint Table with a can of radius 3 cm and height 10 cm.
| Trial | Cone-fuls to fill the can |
|---|---|
| First fill | 3 |
| Second fill | 3 |
| Third fill | 3 |
| Solid | Volume (cubic cm) |
|---|---|
| Can | 282.6 |
| Cone | 94.2 |
282.6 ÷ 94.2 = 3. The pouring and the formulas agree.
- Read the question.
- Tap your answer.
A bigger cone has radius 4 cm and height 9 cm. What is its volume in cubic centimeters? (Use 3.14 for π.)
The matching can has radius 4 cm and height 9 cm. What is its volume in cubic centimeters? (Use 3.14 for π.)| Statement | True or false? |
|---|---|
| The cone and the can must share the same radius and height for the test. | ? |
| Leveling the rice before pouring makes each cone-ful the same. | ? |
| Two cone-fuls fill the can. | ? |
Your pours matched the formula. Tomorrow a tile diagonal gives a number that never ends.