standard_description: Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.
problem_activity: Stage 2: Ones Cubes
Required Preparation
Materials to Gather
Base-ten blocks
Materials to Copy
Blackline Masters
Grab and Count Stage 2 Recording Sheet

Narrative
Each student grabs a handful of ones cubes and puts them together with their partner’s. They estimate how many cubes there are and then count the cubes. Students record their estimate and the actual number of cubes on the recording sheet.
Variation:
Students can count their own group of cubes first and record an equation to represent the total number of cubes.
Additional Information
Each group of 2 needs around 80 ones cubes from the base-ten block set.


aligns: no