Grade 4 · Unit 5: Using units of measurement

Area

Square centimetres and square metres.

Tiling a floor

A floor is covered with square tiles. Counting tiles tells us the area. Area is measured in square units.

Area of a rectangle

Count the rows and columns. Area = length × width. 7 × 4 = 28 cm².

Rectilinear shapes

Split the shape into rectangles. Find each area: 5 × 2 = 10 and 2 × 2 = 4. Add: 14 square units.

Same perimeter, different area

All these rectangles have a perimeter of 20. Their areas are different! The square (5 × 5) has the biggest area.

Irregular areas

A lake or a leaf is not a rectangle. Count whole squares, then add up the half squares. Each square here is 1 cm²: the area is about 17 cm².

What I learnt

• I can find area with A = l × w.
• I can find areas of rectilinear shapes.
• I know perimeter and area are different.