What does a child have to do to calculate area in the 11+?

Calculate the area of a rectangle or decomposable rectilinear shape. It is one of 55 named maths skills in the 11+, in the measure strand, and this page carries 1 interactive exercise that practises it.

What is the trap in an 11+ calculate area question?

The distance round the edge is the perimeter; the area counts the squares that fit inside. The wrong answers on this skill are built out of that, not out of random numbers, so it is worth naming out loud before your child meets it under time pressure.

Is calculate area the same as calculate perimeter?

No. To calculate area is to calculate the area of a rectangle or decomposable rectilinear shape. To calculate perimeter is to calculate the boundary length of a labelled rectilinear or polygonal shape. Learners may apply an area operation to a boundary-length task. Telling the two apart is often the real difficulty in the question.

What is not part of calculate area in the 11+?

The skill map draws the line here: Excludes volume. A question past that line is testing a different named maths skill, which is worth knowing before you spend a week practising the wrong one.

Which other 11+ skills should we practise alongside calculate area?

The skill map connects it to calculate perimeter. Both use labelled dimensions but measure different attributes. That skill has its own page here.

How can my child practise calculate area for free?

Use Area Unfolder, embedded on this page. It is the exercise the skill map attaches to calculate area, it runs in the browser with no account to make, these exercises are not scored and do not save learner records. The separate quiz sends answers for marking and shows a score, without saving an assessment record. It also has its own link, so you can send it to a child without sending them anywhere else first.

Maths · Measure

Calculate area

Calculate the area of a rectangle or decomposable rectilinear shape.

Watch the worked example

Open the video page

Area: Measure the Space Inside

This video shows how to find the area of a rectangle or split a compound rectilinear shape into smaller rectangles. Watch an 11+ maths question solved step by step.

0:00 / 2:45

Turn on captions with the CC button. Jump to any part with the chapter buttons.

Read the transcript

Keep practising with Trace Learn. Find topics to practise next

Quick quiz: Calculate area

10 questions, with feedback after each one. No sign-up needed.

Read the questions in this quiz

Question 1
Femi covers this shape with 1 cm squares. What is the area?
- A.40 cm²
- B.20 cm²
- C.64 cm²
- D.100 cm²
Question 2
Femi covers this shape with 1 cm squares. What is the area?
- A.26 cm²
- B.66 cm²
- C.102 cm²
- D.165 cm²
Question 3
Nadia covers this shape with 1 cm squares. What is the area?
- A.117 cm²
- B.69 cm²
- C.22 cm²
- D.44 cm²
Question 4
Bruno covers this shape with 1 cm squares. What is the area?
- A.23 cm²
- B.97 cm²
- C.132 cm²
- D.46 cm²
Question 5
Kofi covers this shape with 1 cm squares. What is the area?
- A.72 cm²
- B.20 cm²
- C.54 cm²
- D.100 cm²
Question 6
Bruno covers this shape with 1 cm squares. What is the area?
- A.46 cm²
- B.132 cm²
- C.23 cm²
- D.78 cm²
Question 7
Callum covers this shape with 1 cm squares. What is the area?
- A.24 cm²
- B.105 cm²
- C.135 cm²
- D.60 cm²
Question 8
Amara covers this shape with 1 cm squares. What is the area?
- A.48 cm²
- B.19 cm²
- C.88 cm²
- D.38 cm²
Question 9
Amara covers this shape with 1 cm squares. What is the area?
- A.100 cm²
- B.48 cm²
- C.140 cm²
- D.24 cm²
Question 10
Femi covers this shape with 1 cm squares. What is the area?
- A.81 cm²
- B.20 cm²
- C.40 cm²
- D.99 cm²

Practise it now

This L-shape is awkward. Cut it into two rectangles you CAN measure.

Loading the interactive exercise. Nothing you do here is saved or scored.

A worked example

One question of the kind this skill is tested with, worked all the way through: the reasoning, and what the wrong answers are there to catch.

Counting the squares inside a shape

Esme covers this shape with 1 cm squares. What is the area?

Every side of this rectangle is marked in centimetres.

84 cm²
96 cm²
19 cm²
38 cm²

Answer: 84 cm²

How you get there

This rectangle is 12 cm by 7 cm, and 12 rows of 7 squares is 84 squares, so the area is 84 cm². The 38 cm right round the edge is the perimeter, which is a different measurement.

Why the other answers tempt

The distance round the edge is the perimeter; the area counts the squares that fit inside.

If they are stuck, say this

Cut the shape into rectangles you can measure, work out how many centimetre squares each one holds, then add those together.

Now do it live in Area Unfolder

Kitchen-table script for parents

Try this together

A friendly mini script for the breakfast table, school run or a quiet two minutes. Read it aloud as written, or make it your own.

Ready? Let's have a go at Calculate area together. Take a look at the picture. Here is what matters: Every side of this rectangle is marked in centimetres. Here comes the question: Esme covers this shape with 1 cm squares. What is the area? Before we race ahead, let us choose one good first step. Here is a helpful clue: Cut the shape into rectangles you can measure, work out how many centimetre squares each one holds, then add those together. Nice work. Now let us follow the thinking: The 38 cm right round the edge is the perimeter, which is a different measurement. So our answer is: 84 cm². There is one sneaky trap to watch for: The distance round the edge is the perimeter; the area counts the squares that fit inside. Can you show me that first move again in your own words? Brilliant. No rush; we are practising a method you can reuse, not trying to win a speed contest.

What this exercise is doing

Area Unfolder

This L-shape is awkward. Cut it into two rectangles you CAN measure.

A compound shape has no area formula of its own, so you make one: slice it into rectangles, find each area with width × height, and add. Perimeter is a different animal - it is the distance an ant walks all the way round the outside, so the cut you drew does not count. That is why area and perimeter almost never match.

Step 1. Slice it. Cut the shape into two rectangles, then add their areas.
Step 2. The ant walk. Walk the ant right round the edge. How far did it travel?

What to say if they get stuck

Drag along one of the faint grid lines inside the shape to make your cut.
A good cut leaves two neat rectangles - no L-shaped leftovers.
Area adds up when you cut. Perimeter does not: cutting makes new edges that were never on the outside.

Open Area Unfolder on its own page to share it

Where calculate area sits in the 11+

The 11+ does not test these skills in isolation, and practising one in the wrong order wastes the practice. These are the skills the curriculum map connects this one to.

Commonly mixed up with: Calculate perimeter
Learners may apply an area operation to a boundary-length task.
Sits alongside: Calculate perimeter
Both use labelled dimensions but measure different attributes.

How calculate area differs from the skills beside it

The same exercise practises one other skill, and telling them apart is often the difficulty rather than the exercise itself. On this page the skill is: calculate the area of a rectangle or decomposable rectilinear shape, and it stops where excludes volume.

Calculate perimeter
Calculate the boundary length of a labelled rectilinear or polygonal shape. Includes finding a missing side when uniquely determined.

Related maths skills

Calculate a durationFind elapsed time between two clock or timetable entries.
Convert unitsConvert one measure between compatible metric or time units.

All maths 11+ skills

Questions parents ask about calculate area

What this skill involves, common mistakes and ways to practise it at home.

: Calculate the area of a rectangle or decomposable rectilinear shape. It is one of 55 named maths skills in the 11+, in the measure strand, and this page carries 1 interactive exercise that practises it.
: The distance round the edge is the perimeter; the area counts the squares that fit inside. The wrong answers on this skill are built out of that, not out of random numbers, so it is worth naming out loud before your child meets it under time pressure.
: No. To calculate area is to calculate the area of a rectangle or decomposable rectilinear shape. To calculate perimeter is to calculate the boundary length of a labelled rectilinear or polygonal shape. Learners may apply an area operation to a boundary-length task. Telling the two apart is often the real difficulty in the question.
: Point at the next move rather than explaining the whole rule. Cut the shape into rectangles you can measure, work out how many centimetre squares each one holds, then add those together.
: The skill map draws the line here: Excludes volume. A question past that line is testing a different named maths skill, which is worth knowing before you spend a week practising the wrong one.
: The skill map connects it to calculate perimeter. Both use labelled dimensions but measure different attributes. That skill has its own page here.
: Use Area Unfolder, embedded on this page. It is the exercise the skill map attaches to calculate area, it runs in the browser with no account to make, these exercises are not scored and do not save learner records. The separate quiz sends answers for marking and shows a score, without saving an assessment record. It also has its own link, so you can send it to a child without sending them anywhere else first.

Is it calculate area they find hard, or telling it apart from calculate perimeter?

Those two look like one weakness on a practice paper and need completely different practice. A free diagnostic tells them apart across all four subjects.