Balancing
http://illuminations.nctm.org/LessonDetail.aspx?ID=L40
A lesson plan for grades 1–2 Mathematics
In this lesson, the fourth of a six-part unit from Illuminations, students are encouraged to explore another model of subtraction—the balance. This model leads naturally to recording with equations. Students use actual and virtual pan balances in their explorations and record the modeled subtraction facts and the related addition facts in equation form.
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.
