A tenth is one part of something that's been divided into ten equal pieces. If you split a pizza into ten slices, each slice is one tenth of the pizza. If you have ten dollars and spend one, you've spent one tenth of your money.

You write a tenth as the fraction 1/10 or as the decimal 0.1. Ten tenths make a whole. Understanding tenths is essential for working with decimals: 0.3 means three tenths, 0.7 means seven tenths, and so on.

Tenth also means the position in a sequence: if you finish tenth in a race, nine people finished ahead of you. The tenth chapter of a book comes after the ninth and before the eleventh.

Musicians use the word differently: a tenth is an interval spanning ten notes on a scale. When two notes are a tenth apart, they create a bright, open sound. You might hear tenths in piano music, where the left hand plays low notes while the right hand plays notes much higher up the keyboard.