What is an integer?

Question

What kind of number is an integer? Please give an example. – A reader, Canada

Answer

Integers vs. decimals and fractions

An integer, also called a "round number" or “whole number,” is any positive or negative number that does not include decimal parts or fractions. For example, 3, -10, and 1,025 are all integers, but 2.76 (decimal), 1.5 (decimal), and 3 ½ (fraction) are not.

Guidelines for writing numbers in prose (in running text)

In written sentences, integers lower than 10 are usually written as words. Integers of 10 or higher can be written as numbers. Decimals are not written as words, but they can be if they are changed to fractions.

• The two candidates argued constantly throughout the debate.
• Approximately 4,000 ballots were missing. 
• Add 1.5 cups of water to the mix.  OR  Add one and a half cups....  (not "one point five")

For very large numbers, it is common to spell out the word million, billion, etc., for easier comprehension.

• Profits for the year exceeded $7 million. Profits for last year were $6.2 million.

If a number begins a sentence, it is usually written as a word. However, avoid beginning a sentence with a decimal number. Instead, change it to a fraction or change the word order of the sentence.

• Twenty-eight seats were empty on the plane. 
• Two and a half hours was a long time to wait. (not "two point five hours")

Help with writing the time of day:

• How to write the time