A decimal is a fractional number and is indicated by digits after a period which is called a decimal point. Tenths have one digit after the decimal point.
Hundredths have two digits after the decimal point.
Thousandths follow a similar pattern. They have three digits after the decimal point. There may be zeros after the decimal point. A decimal number may be larger than 1. The word and may be used to indicate the decimal point so it should not be used in other parts of the name of the decimal.