How many significant figures are in 0.2434 meters?

How do I determine the number of significant figures in in 0.2434 meters?

There are four significant digits in 0.2434. All non-zero digits are significant. The leading zero is there only by convention.

Remember  the rules for significant figures regarding counting of zeroes 

1.leading zeroes are never counted       -- eg  0.387

2.Zeroes in between the digits are always counted --- eg  308

3. Trailing zeores after decimal always counted ....eg 308.00

4.Trailing zeoes without decimal never counted......eg 30800