standard_description: Use coordinates to prove simple geometric theorems algebraically. For example, prove or disprove that a figure defined by four given points in the coordinate plane is a rectangle; prove or disprove that the point (1, Ö3) lies on the circle centered at the origin and containing the point (0, 2).
problem_activity: Stage 5: Add within 100 without Composing
Required Preparation
Materials to Gather
Paper clips
Two-color counters
Materials to Copy
Blackline Masters
Five in a Row Addition and Subtraction Stage 5 Gameboard

Narrative
Partner A chooses two numbers and places a paper clip on each number. They add the numbers and place a counter on the sum. Partner B moves one of the paper clips to a different number, adds the numbers, and places a counter on the sum. Students take turns moving one paper clip, finding the sum, and covering it with a counter.
Two gameboards are provided, one where students add a one-digit and a two-digit number and one where they add a two-digit and a two-digit number.
Additional Information
Each group of 2 needs 25 counters and 2 paperclips.


aligns: no