1. What is the difference between significant figures and decimal places?

When working out significant figures, start at the first non zero digit.

When working out decimal places, start at the decimal point.

2. When writing a number such as 530 046, correct to 3 sig.figs do the zeroes count?

Yes, the answer is 530 000

3. How about when writing a number such as 0.0530046, correct to 3 sig.figs do the zeroes in front of the 5 count?

No,the answer is 0.0530