Answer:
Explanation:
There really are no steps. You just have to know the rules.
A
There are 2 digits in 2.5 so there are 2 sig digs.
B
There are 3 digits in 5.32 so there are 3 sig digs
C
Here is your first tricky one. There is either 3 or 4 sig digits. In fact the zero counts: there are digits to the left of the zero. So the zero is one of the sig digs. There are 4.
D
This one is even nastier. there are no none zero numbers to the left of the 0. This zero does not count. There are only 2 sig digs.
