The person in the word problem wants to run a total of 1000 miles in a year and within a 2 month process she ran a total of 231.05 miles, so now they are asking how many more miles she has to run in the year to reach her goal of 1000 miles. So I think I should subtract 231.05 miles from 1000 miles.

I would do that, also.

This sounds dumb but do I take

1000-231.05 or 231.05- 1000

If I do it on a calculator I get 768.95, if I set it up with 231.05 on top and the 1000 on the bottom I get 221.05. Something doesn't seem right.

put this in the Google search window

1000-231.05

In case you've not used the google calculator, the 1000 goes on top and the 231.05 goes on the bottom BECAUSE you have 1000 miles total and you have already run 231.05 so 1000 - 231.05 is what you have left to run.

If I do this on my calculator, I get
1000-231.05 = 768.95
If I subtract 231.05-1000 I get -768.95 so you must have punched the wrong numbers when you did it. In the second example I have done, the negative sign tells you that you DON'T have negative miles to run. Right?

Yes, you are correct. To determine how many more miles the person needs to run to reach her goal of 1000 miles for the year, you would subtract the number of miles already run (231.05 miles) from the total goal (1000 miles).

The calculation would be:

1000 miles - 231.05 miles = 768.95 miles

Therefore, the person still needs to run approximately 768.95 miles to reach her goal of 1000 miles for the year.