5^m=64.
Take logs to base 5: m=log₅(64)=2.584
OR
Take logs to a different base, e.g., natural logs:
mln(5)=ln(64), m=ln(64)/ln(5)=4.1589/1.6094=2.584.
If you have a scientific calculator with natural logs on it, you should be able to use the second method. Some calculators allow you to find logs to any base. It doesn’t matter which base you use, the answer will be the same.