The one idea
A standard method from Exponential and logarithmic functions: the steps.
Steps
log is the reverse of a power. "logₐN = x" means "aˣ = N". So log₂32 asks "2 to what power is 32?" Answer: 5.
For the whole topic, read Exponential and logarithmic functions: key points, common mistakes and how the DSE tests it.