▶ S.I. (International System of Units)

S.I. stands for the International System of Units (from the French Système International). It is the standard system of measurement used around the world in maths, science, and engineering.

The S.I. system includes basic units such as:

• metre (m) for length

• kilogram (kg) for mass

• second (s) for time

• ampere (A) for electric current

• kelvin (K) for temperature

• mole (mol) for amount of substance

• candela (cd) for light intensity

Using S.I. units ensures measurements are consistent and understood globally.

Key Idea: S.I. is the universal measurement system used worldwide.