A legal convention requires to repeate a spelled-out number in the numerical form. Always put the numeric representation in parentheses after the spelled out quantity. (Notice that in Russian legal documents this order is reverse).
Incorrect
USD20,000 (twenty thousand)
Correct
Twenty thousand US dollars (USD20,000)

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. The decimal 0.8 is pronounced "eight tenths" or "zero point eight". It is equal to the fraction 8/10.

Hundredths have two digits after the decimal point. The decimal 0.36 is pronounced "thirty-six hundredths" or "zero point thirty-six". It is equal to the fraction 36/100.

Thousandths follow a similar pattern. They have three digits after the decimal point. The decimal 0.749 is pronounced "seven hundred forty-nine thousandths" or "zero point seven forty-nine".

There may be zeros after the decimal point. The decimal 0.064 is pronounced "sixty-four thousandths" or "zero point zero sixty-four".

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. The decimal 234.987 could be pronounced Two hundred thirty-four AND nine hundred eighty-seven thousandths.