How many significant figures does the number 12 have

2

Step-by-step explanation:

There are 2 digits needed to nail down the precise value of 12: a 1 in the tens place and a 2 in the ones place, giving it 2 significant figures.

For a few more examples, the number 1.23 would have 3 significant figures, the number 56.89 would have 4, and the number 1.00000 would have 1, as the trailing zeroes don't contribute anything to the number's actual value.

It has 2.

Step-by-step explanation:

Since the numbers aren't zeroes they are automatically significant figures.