Ocean maths quest: area
A story-led junior maths adventure using reefs, ships and underwater maps to cover floors, gardens and maps with squares.
Quick answer
You can find the area of a shape by counting how many square units fit inside it, or by using a formula like length times width for rectangles.
Learning outcome
By the end of this page, you will be able to find the area of rectangles by counting squares or using multiplication.
- You can count squares to find how much space a shape takes up
- You can use the formula: area = length × width
- You can solve real-life problems about area, like planning a garden or a ship’s deck
- You can compare different shapes to see which has the biggest area
Why this matters
Knowing how to find area helps you solve puzzles, plan your space, and understand the world around you. Whether you are designing a reef for a fish tank, planning a ship’s deck, or drawing a map, area helps you measure how much space something takes up. It's used in real life for building houses, making clothes, and even planning a party!
How it works
Area is the amount of space inside a shape. To find the area of a rectangle:
- Count how many small squares fit inside the rectangle
- Or multiply the length by the width
- For example, a rectangle that is 4 squares long and 3 squares wide has an area of 4 × 3 = 12 squares
Examples you can see
Imagine you are exploring an ocean map and you find a treasure chest. The chest is shaped like a rectangle. You want to know how much space it takes up.
| Length | Width | Area (Length × Width) |
|---|---|---|
| 5 squares | 3 squares | 5 × 3 = 15 squares |
| 6 squares | 4 squares | 6 × 4 = 24 squares |
| 2 squares | 8 squares | 2 × 8 = 16 squares |
You can also draw a rectangle on paper and count the squares inside. This is called using a grid. For example, if you draw a rectangle that is 3 squares long and 5 squares wide, you count 15 squares total.
Try it as a mini adventure
Imagine you are Captain Ocean, a brave explorer. You find a map of an underwater reef. The map shows a rectangular area where you can build a new coral garden. You need to figure out how much space you have to plant.
Your map shows a rectangle that is 6 squares long and 4 squares wide.
4th time: Count the squares to find the area. What is the area of your coral garden?
5th time: Now try multiplying 6 × 4 to check your answer. Is it the same?
6th time: You also find a small rectangular ship’s deck. It is 5 squares long and 3 squares wide. What is the area of the deck?
7th time: Compare the two areas. Which one is bigger?
Common mistakes
- Mistake: Forgetting to multiply length and width, and just adding them together.
Why it happens: Children might think addition works like area, but it doesn’t.
Fix: Use a grid to count squares and then try multiplying to see if you get the same answer. - Mistake: Counting the edges of the shape instead of the inside space.
Why it happens: It’s easy to count the sides when you're looking at a shape.
Fix: Focus on the inside space and count only the squares inside the shape. - Mistake: Thinking area is the same as perimeter.
Why it happens: Both are measurements of shapes, so they can get mixed up.
Fix: Remember, area is the space inside, and perimeter is the distance around the outside.
Parent and carer guide
Help your child understand area by using everyday objects:
- Draw rectangles on grid paper and count squares together
- Use tiles or blocks to build rectangles and count them
- Measure a table or floor space using a ruler and calculate the area
- Play games like "How many square tiles fit in your room?"
- Encourage them to explain how they found the area
Watch out for confusion between area and perimeter. Ask questions like: "What do you need to measure to know how much space you have to paint?" (area) and "What do you need to measure to know how much fencing you need?" (perimeter).
Practice questions
- What is the area of a rectangle that is 5 squares long and 2 squares wide?
- A rectangle is 7 squares long and 4 squares wide. What is its area?
- You have a garden that is 6 squares long and 3 squares wide. What is its area?
- How much space does a rectangle that is 8 squares long and 5 squares wide take up?
- Which is bigger: a rectangle that is 4 squares long and 3 squares wide, or one that is 2 squares long and 6 squares wide?
Answers:
- 5 × 2 = 10 squares
- 7 × 4 = 28 squares
- 6 × 3 = 18 squares
- 8 × 5 = 40 squares
- 4 × 3 = 12 squares; 2 × 6 = 12 squares. They are the same.
FAQ
What is area?
Area is the amount of space inside a shape. It’s measured in square units, like square tiles or square centimeters.
How do I find the area of a rectangle?
You can either count the squares inside it or multiply the length by the width. For example, a rectangle that is 5 squares long and 3 squares wide has an area of 5 × 3 = 15 squares.
Can I use area to plan a garden?
Yes! If you know the area of your garden, you can plan how many flowers or vegetables you can plant.
Why is area important?
Area helps us understand how much space something takes up. It’s used in real life for building, decorating, and planning.
What if I don’t have a grid?
You can still estimate the area by drawing a grid or using small objects like blocks to cover the shape and count them.