One of the rules of significant figures is that leading zeros are not significant; therefore, 0.00034 will only have TWO significant figures (3 and 4).
4 sig figs the ending zero is not significant unless it was a measurement and the zero was an estimation that was part of the measurement.
3 sig figs.
there are 3 sig figs. 4, 0, and 5 are the sig figs
5 sig figs
101.002
There are four sig figs in 1.032
There are four sig figs in 2.905.
There are 4 sig figs in 20.13
There are four sig figs in 60.55.
There are eight sig figs in 57.115102.
There are three sig figs in 4890.
There are two sig figs in 290.