What is 3 significant digits in the number 5.0307

The 3 significant digits in the number 5.0307 are 5.03.

To determine the 3 significant digits in the number 5.0307, we count from the leftmost non-zero digit until we have 3 digits:

5 . 0 3 0 7

The digits 5, 0, and 3 are the three significant digits in the number 5.0307.