**1. What is a litre?**

Think of a litre as the space occupied by a cube of side 10 cm.

**2. How can I convert units from one system to another e.g. metres into feet?**

There are so many different systems in different countries and cultures that it is impossilbe to remember them all. A useful website is called

MegaConvertor.

**3. Who started the metric system?**

The French introduced the metric system shortly after the French Revolution in the 1790s.

**4. How far is a metre?**

A metre was initially defined a one ten millionth of the distance from the equator to the North Pole on a line running through Paris.

**5. Which are the most commonly used prefixes?**

Kilo − 1000 times the base unit

centi- 1/100th of the basic unit

milli- 1/1000th of the base unit

**6. How heavy is a gram?**

A gram is not much at all!

A small drop of liquid would weigh just a few grams.

**7. What is a tonne?**

A tonne is a mass of 1000 kg, which is the weight of a small truck.

**8. What is the difference between mass and weight?**

For mathematical purposes the mass and the weight are the same.