decimal number	Decimal numbers are numbers whose place value is based on 10s, including whole numbers and decimal fractions, which have decimal points and digits to the right of the decimal point. The numbers 18, 4.12 and 0.008 are all decimal numbers.
trailing zero	A placeholder 0 that occurs after the final non-0 digit in a decimal number. In the number 22.0900, the 0s in the thousandths and ten-thousandths places are trailing zeros.