not coming out right in my calculator

you should never do all your math on the calculator. If you put a whole equation in, chances are you will get an incorrect answer. Do your small arithmetic equations by the calculator, jot them down as notes or keep them in your mind, and then simplify by substituting the small arithmetic equations into the actual equation.

6.67x10^(-11)((90)(5.97x10^(24)/6378))
(6.67x10^-11)((90)(936030103480714957666.980244590780809298))
(6.67x0.00000000001)(84242709313264346190028.22201317027283682)
5618988711194.731890874882408278457198215894
simplify

5,618,988,711,194.73

I hope this helps. Of course, this may be incorrect so do not simply take my answer and not check.

jake:

6.67x10^(-11)((90)(5.97x10^(24)/6378))

Someone is definitely correct with their statement:
We did get different answers so I guess it is up to you to work out who made an error.

you should break this up and do some of it separately.
This is how i would do it.
140212 simplifying with sci notation.JPG