Concept of Unit, Number, Numeral and Numeration

Have you ever counted five apples, written “5” on a box, or said “seven” in class? In mathematics, we use specific words for the objects we count (units), the count itself (number), the symbols we write (numerals), and the ways we express numbers with words (numeration).

A unit is the first and the smallest natural number used as a standard of measurement.

Example:

• 1 pen, 1 boy, 1 meter, 1 day.
• Unit of length: 1 meter
• Unit of weight: 1 kilogram

A number is a count or an amount. It tells you how many things there are.

Examples:

• 3 (means "three items")
• 15 (means "fifteen items")
• 72 (means "seventy-two items")
• 0 (means none or nothing)

A numeral is how we write a number.

Examples:

• 3 is the numeral for three.
• 15 is the numeral for fifteen.
• 72 is the numeral for seventy-two.

Numeration is the way a number is expressed in words or through a language system.

Examples:

• 3 is written as three in words.
• 15 is written as fifteen.
• 72 is written as seventy-two.

• When you fill out a cheque, you write the amount in figures (numerals) and in words (numeration).
• Supermarkets use units for items (“1 packet”) and numbers for (“5 packet” bought).

• Number: Answers “how many?”
• Numeral: The way a number is written (symbols).
• Numeration: The way a number is spelled out (words or language system).
• Unit: Always refers to one of something.

Memory tip:
“Unit = ONE. Number = HOW many. Numeral = SYMBOLS. Numeration = WORDS.”