Expert: Josh - 3/23/2009

Question
Hello:
I have a question regarding "mills." There are 1000 mills per United States American $1.00.

13 mills divided by 1000 mills/$1.00 = $0.013 or $0.013/$1.00

If 13 mills equal $1.00 American dollar, would the following calculations make sense?

1. 13 mills = $0.0195/$1.50

2. 13 mills = $0.0065/$0.50

I thank you for your follow-up reply.  

Answer
Hi Kenneth,

Mills is short for "milli", it is not a currency as in an American dollar. It is a scientific unit equivalent to (1 one thousandth, or 1/1000) and can be applied to any number regardless of what it represents, whether we are talking about Canadian dollar, or a length measure like meter. I think you would have come across the unit millimeter as in "mm".

It is generally not a good idea mixing units with an equation and pose questions as such. Only the person writing this knows where he/she is pulling the numbers from. Maths is about logical expression, a stand alone equation does not always impart meaning or necessarily explains what a person is doing. There are, of course, situations where the use of units would make sense. Like in chemistry entropy calculation, to calculate the concentration of a compound or the amount of heat generated in a reaction, as in dimension analysis.

As far as mathematics is concerned, any numerical expression that checks out is true. It is true that 13 x 10^-3 = 0.0065/0.5. The part where I wrote "10^-3" represents a multiplier of 0.001. In the proper context, you can interpret it as "milli" too.