How many significant digits does 230. have?

Gotta admit this is a pet peeve of mine...

Explanation:

Whomever wrote this question wants you to say three sig figs. The way they are writing this number is not considered a correct form by many scientists. If your teacher wrote it this way, it's probably because they were taught that way...

The correct way to write the number two hundred and thirty with three sig figs is:
$2.30 x {10}^{2}$

Writing the number 230 without a decimal would indicate just two sig figs (just the two and the three, the zero is not significant).