You can
put this solution on YOUR website!To evaluate a log that doesn't have a base of 10, you would use the change of base formula

Where the logs on the right are logs of base 10. So if I have

It would look like this with the change of base formula

So if we evaluate log(1000) we get 3 (10^3=1000) and if we evaluate log(2) we get 0.30103 approximately
So

Approximately
So

(or the log base 2 of 1000) is approximately equal to 9.96578
Check:

If we plug in 9.96578 for x we should get 1000

Which is very close to true, since we have round off errors this is good enough.
Hope this makes sense.