standard_description: Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8.
problem_activity: Task
You will need various items to measure, a large set of cubes such as unifix or snap cubes, and a recording sheet with 4 sections. In each section would be the words: _______ cubes long with enough space for a small drawing. The students work in pairs. They choose an item to measure. First they line up the cubes along the longest side of the item. They count and record the number on the first line in the first section. They draw a picture of the item they measured. They continue same routine 3 more times with different items.
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aligns: no