**Post 12/29 in the Staffrm #29daysofwriting challenge: Why use Z to represent integers?**

The set of integers is denoted with the letter Z (rather than I) because

*Zahl*(pl.

*Zahlen*) is the German word for a number. Probably quite useful, as otherwise we'd be struggling for a letter to use for imaginary numbers. There's suggestion that the reason Z stuck for the integers is because two of the most influential number theorists, Euler and Gauss, were both German and both used Z to represent the set of integers in their mathematical writing.

Incidentally, the word

*integer*comes from the root verb

*tangere*(to touch), and with the prefix means

*intact*or

*whole*- hence, the integers are the set of whole numbers. We also get the word

*integrity*, which has the meaning of being whole or undivided.

That's your lot for tonight - I'm now going to veg in front of the telly for a couple of hours before sleeping for, like, a week.

*(Image credit: By Joxemai - Own work, CC BY-SA 3.0, commons.wikimedia.org/w/index....)*