There are a number of units that can be used to describe mass, from pounds, ounces and tonnes to stones and grams. We are going to focus on the most common of these which is the metric measurement * Grams*.

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

**Kilo**gram - Kilo means 1000 so **1kg = 1000g**

**Centi**gram - Centi means 100 so **1cg = 100g **(This one is very very rarely used)

**Milli**gram - Milli means 1000 so **1g = 1000mg**

**How to convert.**

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

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

**Example 1: Convert 150 g to kg.**

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

1000g = 1kg 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 kilogram is bigger than a gram, so there will be less of them overall.

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

150 ÷ 1000 = 0.15 kg

**Example 2: Convert 280g to milligrams.**

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

1000mg = 1g 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 milligram is smaller than a gram, so there will be more of them overall.

As there is more of them, we need to multiply

280 x 1000 = 280000 mg