Lesson 15
Situations Involving Area
Lesson Purpose
The purpose of this lesson is for students to use partial quotients to solve division problems that involve tiling squares and finding a side length of a rectangle with a known area.
Lesson Narrative
In this lesson, students encounter division as they find a side length of a rectangle whose area is a three-digit number and one side is a one-digit number.
The context involves tiling rectangles with square tiles. This enables students to connect the dividend to the number of tiles in the rectangle and the divisor to the number of rectangles along one side. The grid provided in the first activity encourages students to partition the area (the dividend) into smaller parts, which in turn facilitates finding the unknown length (the quotient).
- Representation
- MLR7
Activity 1: Elena’s Mural
Learning Goals
Teacher Facing
- Reason about division of two- and three-digit numbers in situations involving area of rectangles.
Student Facing
- Let’s divide to find the side length of a rectangle.
Required Materials
Materials to Gather
Required Preparation
Activity 2:
- If doing a gallery walk, create 3–4 posters to display during the activity that show or describe different strategies students are likely to use to solve the problem.
CCSS Standards
Lesson Timeline
| Warm-up | 10 min |
| Activity 1 | 15 min |
| Activity 2 | 20 min |
| Lesson Synthesis | 10 min |
| Cool-down | 5 min |
Teacher Reflection Questions
Which questions that you asked today would you rephrase to improve students’ ability to make connections or to help them better consolidate what they did? How would you rephrase them?
Suggested Centers
- Compare (1–5), Stage 4: Divide within 100 (Supporting)
- Rolling for Fractions (3–5), Stage 2: Multiply a Fraction by a Whole Number (Supporting)