a) 1400 has 2 significant figures, zeros are no consider as significant figures
b) 1001 has 4 significant figures, zeros in between two nonzero numbers are significant figures
c) 101.2 has 4 significant figures, zeros in between two nonzero numbers are significant figures. Nonzero number are significant figures
d) 2310 has three significant figures. 2,3 and 1 are significant figures.
