Area of square 10 with a 4 by 4 square cut out

Step by step

The question

Question: find the area of this shape: a 10 square with a 4 by 4 hole cut out.

1 The whole and the hole

The whole shape would be a 10 square.

A hole is cut out.

That part is not there any more.

So we take it away.

2 Area of each part

The whole square: length times width.

10 times 10 is 100.

The hole is a 4 by 4 rectangle.

4 times 4 is 16.

3 Take away the hole

The area is the whole, take away the hole.

100 minus 16 is 84.

So the area is 84 square units.

4 Check

Let's check: put the hole back.

We should get the whole rectangle.

We get 100, the whole square.

So the area is right!

Let's look back.

First: the whole and the hole.

Then: area of each part.

Then: take away the hole.

Last: check.