The template for a logarithm is:
a^c = b
log a b = c
This may not make sense on it's own so I will include an example - see the attachment:
2^3 = 8
log 2 8 = 3
2 cubed (to the power of 3) = 8
2 * 2 * 2 = 8
2, multiplied by itself, goes into 8 3 times.
