Area and perimeter on a grid
The space inside a shape: count squares or use l × b. The distance around a shape, and the formulas for a rectangle and square. Read one part at a time and tap “I know this”. Then test yourself in the quiz.
Know it already? Jump straight to the quiz
Area
Area is the space inside a flat shape. Count the squares, or use a formula.
| Shape | Formula |
|---|---|
| square | s × s |
| rectangle | l × b |
Area units are square: cm², m². Don’t mix it up with perimeter.
On a grid
Count the whole squares, then match up the half squares: two halves = one whole. Example: a shape covers 8 whole squares and 4 half squares, so its area = 8 + 2 = 10 squares.
A right-angled triangle on a grid is half of the rectangle drawn on its two short sides. Otherwise: count the whole squares and match up the part squares.
Perimeter
Perimeter is the distance around a shape. Add all the sides.
- Rectangle: P = 2 × (l + b): 2 × (5 + 3) = 16 cm.
- Square: P = 4 × s.
- Perimeter units are plain: cm, m.
Remember this and test yourself
- Area = space inside a shape.
- Perimeter = distance around a shape.
- Area of a rectangle: l × b.
- Perimeter: add all the sides.
- Area units are square: cm².
- Perimeter of a rectangle: 2 × (l + b); of a square: 4 × s.
Write these points in your book. Read them again the night before the test.
Perimeter is the fence; area is the grass.
Important words
First say the answer yourself, then turn the card over.
Match column A to column B
Tap a word in column A, then its meaning in column B. You can also start in column B.
Now the real quiz!
The quiz has many more questions on this topic. Every question shows straight away whether you are right and explains why.
Take the quiz: Area and perimeter on a grid- Let your child work the examples on paper and explain them to you.
- The ticks (“I know this”) are saved on this device only. We never ask for names or emails.
Follows CAPS for Grade 5 Mathematics. Always check your teacher’s notes and textbook too.