Topic explanation

Standard explanation

The International System of Units, abbreviated as SI, is an internationally accepted and coherent system of measurement based on seven base units.

Key points

• Define the International System of Units.
• Distinguish between a physical quantity, numerical value, and unit.
• Recall all seven SI base quantities and their units.
• write unit names and symbols correctly.
• Distinguish quantity symbols from unit symbols.
• Recognize common mistakes involving capitalization, spacing, plurals, and prefixes.
• Express simple derived units using SI base units.
• SI contains seven base units.

Labelled diagram