Taking away sets
http://illuminations.nctm.org/LessonDetail.aspx?ID=L104
A lesson plan for grades 1–2 Mathematics
This lesson, one of a seven-part unit from Illuminations titled “Links Away,” encourages students to explore another model for subtraction, the familiar set model. Reading one of the many books that feature subtraction sets the stage for this lesson in which the students write story problems, find differences using sets, and present results in a table. In the discussion of the table, they focus on the effects of subtracting all and subtracting 0.
North Carolina Curriculum Alignment
Mathematics (2004)
Grade 1
- Goal 1: Number and Operations - The learner will read, write, and model whole numbers through 99 and compute with whole numbers.
- Objective 1.03: Develop fluency with single-digit addition and corresponding differences using strategies such as modeling, composing and decomposing quantities, using doubles, and making tens.
- Objective 1.04: Create, model, and solve problems that use addition, subtraction, and fair shares (between two or three).
Grade 2
- Goal 1: Number and Operations - The learner will read, write, model, and compute with whole numbers through 999.
- Objective 1.03: Create, model, and solve problems that involve addition, subtraction, equal grouping, and division into halves, thirds, and fourths (record in fraction form).
- Objective 1.05: Create and solve problems using strategies such as modeling, composing and decomposing quantities, using doubles, and making tens and hundreds.
