Unit Plan 14 (Grade 3 Math): Area as Unit Squares—Foundations
Understand area by tiling rectangles with unit squares and counting rows and columns; use arrays and repeated addition to model and label area in square units.
Focus: Define area; tile rectangles with unit squares; connect area to arrays (rows × columns).
Grade Level: 3
Subject Area: Mathematics (Measurement & Data • Operations & Algebraic Thinking)
Total Unit Duration: 5 sessions (one week), 45–60 minutes per session
I. Introduction
Students build a concrete understanding of area as the number of unit squares that cover a surface without gaps or overlaps. They practice tiling rectangles with square units (cm², in²), counting systematically by rows and columns, and connecting these tiles to arrays and repeated addition (a bridge toward multiplication).
Essential Questions
- What is area, and how do unit squares help measure it?
- Why must a tiling have no gaps or overlaps to measure area accurately?
- How do arrays (rows and columns) help me count and represent area?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Define area and explain it as the count of unit squares covering a figure without gaps or overlaps.
- Tile rectangles on grids or with manipulatives and count area by rows and columns.
- Represent area situations with arrays and repeated addition; describe what each number means in context.
- Label answers with correct square units (e.g., cm², in²) and explain their reasoning.
Standards Alignment — CCSS Grade 3
- 3.MD.5: Recognize area as an attribute of plane figures and understand unit square as a unit for measuring area.
- 3.MD.6: Measure areas by counting unit squares (square cm, square m, square in, square ft, and improvised units).
- 3.OA.3: Use multiplication/division within 100 to solve word problems in situations involving arrays and measurement quantities (here, as repeated addition foundations).
- Mathematical Practice: MP.4 (Model with mathematics).
Success Criteria — Student Language
- I can tell what area means and show it with unit squares.
- I can tile a rectangle without gaps or overlaps and count by rows or columns.
- I can use an array and repeated addition to show how I got the area.
- I can write the answer with square units (like cm² or in²) and explain why.