Measuring, Estimating and Units

Hong Kong

Stage 1 - Stage 3

Lesson

When we measure things, the unit of measurement we use depends on what it is we are measuring. We are going to look at three different types of measurement here, as well as the words we use to describe what it is we are measuring.

Capacity is a word to describe how much something holds. We often use this when we think about liquids, though you could use it to describe how many people a sports ground holds, perhaps. Today, we'll be looking at liquids, and comparing some different containers, and how much they hold. The units of measurement we use for capacity are:

- millilitres (mL)
- litres (L)
- kilolitres (kL) and
- megalitres (ML)

If we measure length, we're thinking about how far away one end of something is from the other. We could also be talking about how tall someone (or something) is, or how wide something is. The units of measurement we use for length are:

- millimetres (mm)
- centimetres (cm)
- metres (m) and
- kilometres (km)

When we want to know how heavy something is, we refer to its mass. Some objects may weigh a lot, even though they are very small. Other objects may be very big but weigh very little. Imagine a big bag of feathers- it takes up quite a bit of space but it probably doesn't weight very much. On the other hand, an elephant is big and definitely weights a lot! Often, we call of an object's mass its weight.

In this video, we'll look at all capacity, length and mass and see examples of the units of measurement for each.

Did you know?

'kilo' is used at the start of a word to suggest 'thousand' - a kilogram is $1000$1000grams

'milli' is used at the start of a word to suggest 'thousandth' - a millilitre is $0.001$0.001 of a litre

Look at the picture of the scale to answer the following questions.

What do we measure with a scale like this one?

Mass

ALength

BCapacity

CWhich of these units can we measure with this scale?

Millimetres

ATonnes

BMetres

CGrams

D

Which unit is best to measure how far a person has jumped in the long jump?

Metres

AKilometres

BCentimetres

CMillimetres

D