This is equivalent to asking you "how many powers of 10 are equal to 0.0000 1".

Of course it is -5!

Supplement:

When you see log on the calculator, press log-100, and the result is 2.

Therefore, on the calculator, the log is based on 10, which is basically considered by the international community!

But lg is also a logarithm based on 10.

The logarithm of any base is also expressed by log, but don't forget to enter the base on the calculator.

A few more tugs and you'll understand.