Concept 6 of 9
The Grass Planter: Area
Today's big idea
Area is the space inside, found by multiplying the length by the width.
Same 8 m by 5 m garden holds 8 x 5 = 40 m² of grass.
How it works
👀 What's going on?
Now you want to plant grass inside that same garden. The fence was about the edge. Grass is about everything in the middle, and that turns out to be a completely different question.
💡 Here's the trick
Look at the garden above. It is 8 m wide and 5 m deep. You can lay 8 one-metre tiles along a row, and fit 5 of those rows in. That makes 8 x 5 = 40 tiles, so the area is 40 m². The little 2 is there because the space spreads in two directions at once.
🪄 How to do it
- 1.Read off the length and the width, as the picture above gives 8 m and 5 m.
- 2.Multiply them together, or multiply side by side for a square.
✍️ Try it
A garden measures 7 m by 4 m. A square rug has 6 m sides. What is the area of each?
The garden gives 7 x 4 = 28 m². The rug gives 6 x 6 = 36 m². The rug has a shorter longest side and still covers more ground, because area depends on both directions at once.
⚠️ Watch out
You might be thinking a bigger perimeter must mean a bigger area. The garden above measures 26 m round and holds 40 m². A long thin strip 12 m by 1 m measures the same 26 m round, and holds only 12 m².
🌟 Why this matters
Paint, carpet, tiles, turf and gift wrap are all sold by area, because they have to cover a surface. Getting it wrong means buying half the carpet you actually need.
Exam tip: Area answers carry a squared unit, and a missing m² is a surprisingly common dropped mark.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“A plot 10 m × 7 m. How much grass to plant?”
- 1
Area = space inside
Think of it as 1-metre square tiles filling the plot.
- 2
Use the rectangle formula
Area = length × width. Length is 10, width is 7.
- 3
Multiply
10 × 7 = 70
- 4
Grass needed ✓
70 m² of grass
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
Plant a whole row of grass at a time. Each row is 5 tiles long, so watch the rows multiply as you fill the garden.
length = 5 m
Tap a row to plant 5 tiles
Quick check
✅ VERIFICATION
A rectangle measures 9 m by 4 m. What is its area?
⚡ Finish the activity above first to answer.
Keep going!
Up next: The Data Stamper
Turn a list of numbers into a picture.