UK Primary (3-6) Imperial Units - Weight
Lesson In Introducing the Royal Measurements, we looked at some common imperial units for measuring mass. When we weigh something, we are actually measuring its mass. Mass is a measure of how heavy something is, such as a bag of oranges, a suitcase or even a person.

Here are a list of common imperial measurement units in order from smallest to largest: ounces (oz), pounds (lb), stones (st) and tons (t).

## Converting units

Converting units is an application of ratios. We start by writing the conversion equation and look at how we multiply or divide to find the value of a certain quantity. Make sure your familiar with applications of ratios, then you can look through the following conversion charts, so we can start moving between imperial and metric units.

### Metric units to imperial units

$1$1 gram = $0.035$0.035 ounces

$1$1 kilogram = $2.205$2.205 pounds

### imperial units to metric units

$1$1 ounce = $28.35$28.35 grams

$1$1 pound = $454$454 grams

$1$1 stone = $6.35029$6.35029 kilograms

$1$1 ton = $907.19$907.19 kilograms

Hint

You may have noticed that there are a lot of decimals when converting metric to imperial, or vice versa. To make these conversions easier, just round them to $1$1 decimal place e.g. $1$1kg$\approx$$2.2$2.2lbs.

#### Worked Examples

##### Question 1

Using the conversions in the given table, convert each of these weights from kilograms (kg) to pounds (lbs):

 Conversion Table $1$1 ounce $=$= $28$28 grams $1$1 kg $=$= $2.2$2.2 lbs $1$1 stone $=$= $6.4$6.4 kg
1. $10$10 kg

2. $50$50 kg

3. $18$18 kg

4. $75$75 kg

##### Question 2

Using the conversion $1$1 kg = $2.2$2.2 lbs, how many kilograms is a $3000$3000 lb car?

Give your answer correct to $2$2 decimal places.