Chapter 9.3 (Mathematics 5)

Area of rectangle and square as a product of rows and columns

Print the worksheet for group activities (actual size).

Area of a rectangle

In pairs:

  1. Cut out the rectangle on the worksheet.
  2. Cover the rectangle using one centimetre squares.
  3. Count the number of the one centimetre squares used to cover the rectangle.
     squares
  4. Count the number of one centimetre squares along the length (columns).
     squares
  5. Count the number of one centimetre squares along the width (rows).
     squares
  6. Multiply the number of columns by the number of rows.
    The product is .
  7. Compare the total number of squares counted with the product of number of columns and number of rows.
      
  8. Discuss in your group and share with other groups.

Note

The number of one centimetre squares counted is equal to the product of number of columns and number of rows.

Area of the rectangle = Number of columns × Number of rows

Example 2

Find the area of the rectangle shown below.

Number of columns is 6.
​Number of rows is 4.

Area of the rectangle = number of columns × number of rows = 6 × 4 square centimetres = 24 cm2

Exercise D

Columns are 

Rows are 

Area =  ×  =  cm2

Columns are 

Rows are 

Area =  ×  =  cm2

Columns are 

Rows are 

Area =  ×  =  cm2

Columns are 

Rows are 

Area =  ×  =  cm2

  • 12 cm2
  • 14 cm2
  • 15 cm2
  • 21 cm2

Area of a square

In pairs:

  1. Cut out the square on the worksheet.
  2. Cover the square fully with one centimetre square.
  3. Count the number of one centimetre squares used to cover the square.
     squares
  4. Count the number of one centimetre squares along the length (number of columns).
     squares
    Count the number of one centimetre squares along the width (number of rows).
     squares
  5. Multiply the number of columns by the number of rows.
    The product is 
  6. Compare the total number of one centimetre squares counted with the product of number of columns and number of rows.
      
  7. Discuss in your group and share with other groups.

Note

Total number of one centimetre squares counted is equal to the product of number of columns and number of rows.

Area of a square = Number of columns × Number of rows

Example 3

Find the area of the square shown:

Number of columns is 6.
​Number of rows is 6.

Area of the square is 6 × 6 = 36 cm2.

Exercise E

a)  cm2

b)  cm2

c)  cm2

d)  cm2

a)  cm2

b)  cm2