In Maths next week the children will be calculating & comparing the area of rectangles (including squares). They will be using standard units, square centimetres (cm2) and square metres (m2) and will also estimate the area of irregular shapes.
What is area?
Area tells us the size of a shape or figure. In the real world it tells us the size of pieces of paper, computer screens, rooms in houses, baseball fields, towns, cities, countries, and so on. Knowing the area can be very important. Think of getting a new carpet fitted in a room in your home. Knowing the area of the room will help make sure that the carpet you buy is big enough without having too much left over.
So how do we calculate the area…
The area of a rectangle is = length x width
We can count the squares or we can take the length and width and use multiplication.
This square has a length of 1cm, as it is a square we know that all of the sides are the same length so the width is also 1cm. 1cm x 1cm = 1cm so we say that it has an area of 1cm2 (1cm squared).
This rectangle contains six squares but we can use multiplication to work this out as the length is 3cm and the width is 2cm. 3cm x 2cm = 6cm so the rectangle is 6cm2. (6cm squared)
How many squares are in this rectangle?
What about compound shapes?
There are two different methods for finding the area of this shape:
Divide the shape into squares and rectangles, find their individual areas and then add them together.
Area = 16 + 16 + 48 = 80cm2
Imagine the shape as a large rectangle with a section cut out.
Find the area of the large rectangle (12 × 8) and then subtract the part that has been cut out (4 × 4)
Area = (12 × 8) – (4 × 4) = 96 – 16 = 80cm2
Hope this helps!