1. Who started the metric system?

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

2. 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. It is currently defined as the length of the path travelled by light in a vacuum for a time of 1/299 792 458 th of a second.

3. 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

4. What is a litre?

Think of a litre as a cube of side 10 cm. This gives an volume of 10 × 10 × 10 = 1000cm3

5. What is a tonne?

A tonne is a mass of 1000 kg

6. How is temperature measured?

There are two main units:
Degrees Centigrade: 0
oC = freezing point of water and 100oC = boiling point of water
Degrees Farenheit: 32
oF= freezing point of water and 212oF= boiling point of water
To convert oC to o: multipy by 9/5 and add 32
To convert oF to o: subtract 32 and multipy by 5/9

7. What is a Hectare?

A hectare is an area equivalent to a square of length 100m. i.e. 1 hectare = 100 × 100 = 10 000 m2

8. What is the difference between mass and weight?

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