The thing with logs is, they are reciprocals of powers.
1. So, if something to a power is 10
eg a 2.37 = 10
Then the reciprocal is, the log (to the base of the number you are using in the power) of the answer is the power.
log a 10 = 2.37
2. If you want to change the base from say "10" (assumed if no log base is given) to "2", you divide as shown:
log 10 411= log2411 / log210
=log222(11) / log210
=log2222 / log210
=22/log210