A natural number is any number that is a positive integer, such as 1, 2, 3, 4, and so forth. Often, the number 0 is also called a natural number.

A cardinal number indicates the quantity of things, but not the order in which they occur. By contrast, ordinal numbers are first, second, third, and so on, indicating their positions in a series.

A real number is a number that can be given by a finite or infinite decimal representation. The term "real number" was coined to distinguish it from an "imaginary number." The set of real numbers includes rational and irrational numbers, which can be positive, negative, or zero.

Saros Series 10 Catalog of Solar Eclipse Saros Series NASA Eclipse Web Site. Retrieved October 7, 2022.

Saros Series 10 Catalog of Lunar Eclipse Saros Series NASA Eclipse Web Site. Retrieved October 7, 2022.

Harold Lindsell (ed.), Harper Study Bible: The Holy Bible Revised Standard Version (Grand Rapids, MI: Zondervan Bible Publishers, 1971).