S.I. UNIT

To ensure that our measurements are fair and objective, common standards need to be established. Since 1960, scientists from different parts of the world have agreed to use the Systeme International d’Unites (International System of Units), denoted by ‘S.I.’. Today, S.I. units are the most widely used system of units in Science. Here are the units commonly used in science:

Quantity name	Unit name
length	metre
mass	kilogram
time	second
temperature	kelvin

I feel that S.I. unit is very useful because in ancient Egypt, one cubit was the length from the elbow to the tip of a person’s hand. This is a very inaccurate measurement as different people has different arm lengths.