Chapter 5 · Let's practise geometry

Lesson 5.9 · Square metres

Hua's Classroom for Shanghai Maths — One Lesson One Exercise (English edition, pages 130–132).

Grade 3First Semester Pages 130–132ECNU Press

Lesson Alignment

How this Shanghai Maths lesson connects to learning goals, Common Core, and Eureka Math.

Learning Objectives

Students will be able to:

  1. 01Know the square metre and relate to $\text{cm}^2$.
  2. 02Judge true/false about area, perimeter, and units.
  3. 03Solve large-area problems (wheat field yield).

Common Core Standards

CodeStandard (focus for this lesson)
3.MD.C.5Recognize area as attribute.
3.MD.C.6Measure area by counting unit squares.
3.MD.C.7Relate area to multiplication/addition.
4.MD.A.3*(preview)* Apply area/perimeter formulas.

Eureka Math Correspondence

Shanghai MathsFocusEureka Math
Larger area unitG3 M4 / real-world

Core Concepts

Introduce $\text{m}^2$ for larger spaces and apply to fields.

Square Metre

$$1\ \text{m}^2 = \text{area of a }1\ \text{m}\times 1\ \text{m}\text{ square}$$

Side $100\ \text{cm}$ → area $1\ \text{m}^2$.

Sense of Size

About one pupil can stand in $1\ \text{m}^2$. Perimeter stays fixed if the same wire forms different closed shapes — area can change.

Field Applications

Wheat field width $25\ \text{m}$, length = times width; yield per $\text{m}^2$ → total harvest.

Key Terms & Definitions (Reference)

Quick glossary for this lesson.

TermDefinition
Square metre ($\text{m}^2$)Area of a $1\ \text{m}$ by $1\ \text{m}$ square.
PerimeterDistance around a figure.

Key Answers

Quick reference for this lesson’s exercise answers.

1. $1$ square metre ($1\,\mathrm{m}^2$); $1$ square centimetre ($1\,\mathrm{cm}^2$).

2. Units — $\mathrm{m}^2$; $\mathrm{cm}^2$; $\mathrm{dm}^2$; m; $\mathrm{cm}^2$; $\mathrm{m}^2$; m; $\mathrm{cm}^2$.

3. $40\,\mathrm{m}^2$; $2500\,\mathrm{m}^2$; $18\,\mathrm{m}$.

4. T/F — ✕; ✓; ✓; ✓; ✓.

5–7. $2400\,\mathrm{m}^2$; $75$ yuan; $5000\,\mathrm{kg}$.

8–9. $176\,\mathrm{m}^2$; $640\,\mathrm{m}^2$.