finding averages for neg & pos integers (values in yards)

[mccallum]

I have this problem:
for the group I need to find the average football yardage:
10 yd., -5 yd, 7 yd., 9 yd., -11 yd.

I thought 10+-5+7+9+-11= 10 and then divide 10 by 5 (because there are 5 numbers) and thought the answer should be positive 2 yard average.
Am I doing this right?

 

[Loren]

Re: finding averages for neg & pos integers

I think you have it correct. Except your symbolism should probably be improved. You indicated "10+-5+7+9+-11= 10". It is commonly accepted that you don't place operational symbols next to each other without some separation device. I recommend that you establish the habit of enclosing a negative number within a parenthesis when it is preceded by an operational sign. Make it read "10+(-5)+7+9+(-11)= 10". Likewise, rather than something like 5 -+3, make it 5-(+3). Keep up the good thinking.