standard_description: Give an informal argument using Cavalieri’s principle for the formulas for the volume of a sphere and other solid figures.
problem_activity: Stage 4: Add to 1,000
Required Preparation
Materials to Copy
Blackline Masters
How Close? Stage 4 Recording Sheet
Number Cards (0-10)

Narrative
Before playing, students remove the cards that show 10 and set them aside.
Each student picks 8 cards and chooses 6 of them to create 2 three-digit numbers. Each student adds the numbers. The score for the round is the difference between each student’s sum and 1,000. Students pick new cards so that they have 8 cards in their hand and then start the next round. The player with the lowest score wins.
This center stage is the first time Number Cards 0–10 are used in Grade 3, so they are provided as a blackline master. Students will continue to use these throughout the year. Consider copying them on cardstock or laminating them and keeping them organized to be used repeatedly.


aligns: no