There are a number of units that can be used to describe length, from miles, feet and yards to leagues and metres. We are going to focus on the most common of these which is the metric measurement * Metre*.

All of the units you will have heard of that have the word metre in them are based around the base unit metre with other words tacked on to describe their relationships.

**Kilo**metre - Kilo means 1000 so **1km = 1000m**

**Centi**metre - Centi means 100 so **1m = 100cm**

**Milli**metre - Milli means 1000 so **1m = 1000mm**

Another common conversion that is based on these is that **1cm = 10mm**

**How to convert.**

**Step 1:** Decide on your conversion factor (i.e. m to km is a conversion of 1000)

**Step 2: **Either multiply or divide by this number to get your converted numbers,

**Example 1: Convert 15cm to metres.**

**Step 1:** Decide on your conversion factor.

100cm = 1m so our conversion factor is 100

**Step 2**: Multiply or Divide,

You need to think about this a bit. The way I look at this is that a metre is bigger than a cm, so there will be less of them overall.

As there is less of them, we need to divide.

15 ÷ 100 = 0.15 m

**Example 2: Convert 1.4km to metres.**

**Step 1:** Decide on your conversion factor.

1000m = 1km so our conversion factor is 1000

**Step 2**: Multiply or Divide,

You need to think about this a bit. The way I look at this is that a metre is smaller than a km, so there will be more of them overall.

As there is more of them, we need to multiply

1.4 x 1000 = 1400 m