Volume of cuboids

Hello, and welcome to Myriora Maths! How much space is inside a box? That's called the volume. We can measure it by filling the box with little cubes. Let's see how.

Volume is how many cubes fill a shape. Each little cube is one centimetre on every side. That's one cubic centimetre.

Let's fill this box. The bottom layer is four cubes long and three cubes wide: twelve cubes. The box is two layers tall. Two layers of twelve is twenty-four cubes.

So the volume of a cuboid is length times width times height. Four times three times two is twenty-four cubic centimetres. We write it with a little three.

Let's try one together. A cube is three centimetres on every side. What is its volume? Say it out loud!

Three times three times three is twenty-seven cubic centimetres!

Here's a question that catches lots of people. A box is four by three by two centimetres. What is its volume? Some people add the numbers, and get nine. But volume counts the cubes inside: twelve in each layer, and two layers. Multiply: twenty-four cubic centimetres!

Your turn! A cuboid is five centimetres long, two wide and three high. What is its volume? Pick the right card. You've got twenty seconds, or pause the video. Go!

Time's up! Five times two is ten cubes in each layer. Three layers: thirty cubic centimetres!

Quick review. Volume is how many cubes fill a shape. For a cuboid, find one layer, then times by the number of layers. That's length times width times height. And it's measured in cubic units, like cubic centimetres. See you next time!