Whole number

Whole numbers are the natural numbers with zero added at the start. They have no fractions, no decimals and no negative signs. The smallest whole number is 0. There is no largest one.

The one difference from natural numbers is zero. That sounds small, but zero lets you write an empty count. A class with no absent children has 0 absent, and 0 is a whole number.

A small example

Sort these numbers: 0, 5, -2, 3/4, 18.

• 0, 5 and 18 are whole numbers.
• 5 and 18 are also natural numbers. 0 is not.
• -2 is negative, so it is not a whole number. It is an integer.
• 3/4 is a fraction, so it is not a whole number either.

A quick test: can you reach the number by counting 0, 1, 2, 3 and so on? If yes, it is a whole number.

Why it matters later

Each new kind of number in school contains the last one. Whole numbers sit inside the integers, which sit inside the rational numbers. Class 10 Chapter 1 is called Real Numbers because it works with all of them at once. Knowing where 0 belongs keeps those sets straight.

About the author

Mohit Sardana

Chief Architect

An engineer (B.Tech, Computer Science) with over 20 years of preparing students for entrance exams, including as Dean at FIITJEE and Vice-President at Aakash. He is the chief architect of the TRUpreBoards evaluation engine.

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