Expert: Abe Mantell - 12/26/2010

Question
Hello:

Why are different units (dollars & cents) mixed together when monetary amounts are used?

For example, a gasoline price may be advertised as $2.98(9/10) We would say two dollars and ninety eight & nine tenths cent instead of two dollars and nine hundred and eighty nine thousandths of one dollar.

If the dollar sign is removed, we would say what should be said: two point nine hundred and eighty nine thousandths or simply 2 point 989.

I thank you for your reply.

Answer
Hello Kenneth,

My guess is that since we have currency/coins that are fractions of a dollar (i.e. different cent values), then when money is physically counted we count the number of whole dollars and then the amount of "change" in cents...then it is "natural" to say something like "2 dollars and
98 cents" rather than "2.98 dollars" or "2 and 98-hundreths of a dollar."  Of course, mathematically, "2.98 dollars" is quite correct!  :-)

I hope this answers your question.

Abe