Measurement

Hong Kong

Stage 1

Lesson

You may have learned about estimating and measuring capacity. Capacity is a word to describe how much something holds. We often use this when we think about containers.

Now we will look at comparing objects by their capacity. To compare objects we look at how much they will hold, make sure they are in the same measurement unit (such as litres) and then decide which is larger and which is smaller.

Watch this video to learn about comparing objects by their capacity.

Try these questions for yourself.

Look at the two boxes and their capacities.

Box 1 |
Box 2 |

Capacity $=$=$25$25 L | Capacity $=$=$50$50 L |

Which box is bigger?

Box 2

ABox 1

B

Look at the picture showing three measuring cylinders.

Which cylinder has the greatest capacity?

Cylinder B

ACylinder C

BCylinder A

CWhich cylinder has the least capacity?

Cylinder B

ACylinder A

BCylinder C

CWhich cylinder has the capacity closest to $600$600 mL?

Cylinder C

ACylinder A

BCylinder B

C

We can use our mathematical knowledge to work with capacities. For example, if we have three jugs that each hold $4$4 litres, we can work out three lots of four ($3\times4$3×4) to find the total capacity. $3\times4=12$3×4=12, so the jugs can hold $12$12 litres altogether.

Watch this video to learn more about working with capacities.

Now try these questions for yourself.

Here is a list of the capacities of three different shaped ice cubes.

Type | Capacity (mL) |
---|---|

Star | $13$13 |

Circle | $17$17 |

Square | $18$18 |

Which ice cube holds the most?

The square shaped ice cube.

AThe circle shaped ice cube.

BThe star shaped ice cube.

CIf three of each ice cube was made, which would take the least amount of water to make?

Three square shaped ice cubes.

AThree circle shaped ice cubes.

BThree star shaped ice cubes.

C

Ryan has some friends coming over and wants to make some fruit punch for them to drink.

In his kitchen then are three jugs with the following capacities:

- Jug 1 = $490$490 mL
- Jug 2 = $780$780 mL
- Jug 3 = $410$410 mL

If he wanted to make $760$760 mL of fruit punch, which jug should Ryan choose?

Jug 1

AJug 2

BJug 3

C

Remember!

- The capacity of an object is how much it can hold.
- To compare capacities, look at their total capacity (make sure they are in the same measuring unit), then compare them.
- If you have more than one of a container, use multiplication to work out the total capacity.