Measure area in square units cm² and m²

What you will learn

• Measure area in square units cm² and m²

Models used: number sentences, stories, diagrams.

Before you start

• Draw a line to the nearest centimetre

Covering a surface, or going around it?

The first row has 5 squares. Each square is one unit of area.

1. Each little square is one square unit. There are 5 squares across and 3 rows.

   The first row has 5 squares. Each square is one unit of area.

2. Each little square is one square unit. There are 5 squares across and 3 rows.

   There are three identical rows. Count five, three times.

   5 × 3 = 15 square units

3. Perimeter asks a different question: how far around the outside? Trace all four sides.

   5 + 3 + 5 + 3 = 16 units

Worked example: A new example, together

Find the area of the 7 cm by 7 cm rectangle.

1. Identify the surface to cover and the lengths that determine its rows. Keep missing or overlapping pieces visible.

   Area counts the surface covered by square units, with missing parts removed.

2. The full rectangle covers 7 × 7 = 49 square centimetres.

   Find the area of the 7 cm by 7 cm rectangle.

   49 cm²

3. Each row has the same number of squares.

4. Area = 49 cm².

5. Check the result against the question we started with.

   49 ÷ 7 = 7.

   We found 49 cm². Area counts the surface covered by square units, with missing parts removed.

Common mistakes to discuss

• Counting the boundary. Area counts the squares covering the inside; the squares around the edge are the perimeter’s business.

Check your understanding

• Measure area in square units cm² and m²
• explain area calculations using covered square units
• check the answer against the original quantities and units

Explain your reasoning to an adult, then try a fresh question in the interactive lesson. A result from one attempt is not proof of lasting mastery.