A children’s book sets the stage for this lesson which encourages students to review counting back. In this lesson, children write subtraction problems and model them with cubes. They compare sets and record differences in the form of a table. The additive identity is reviewed in the context of comparing equal sets.
This lesson builds on the previous two lessons and encourages students to explore another model for addition, the set model.
In this lesson, students make sets of a given number, explore relationships between numbers, and write numbers that name how many elements are in a group.
Students construct sets of up to five items, write the numeral 5, identify sets of five, and record “5” on a chart.
The students make sets of pasta shapes and count some away, then record the subtraction in vertical and horizontal formats.