Significant Figures- Significant figures in a measured value of a physical quantity is the number of digits in which we have confidence of their accurate value.

There are some rules to counting significant figures-

1. All non-zero digits are significant.

eg.  45236 has 5 significant figures.

2. All zeroes betweeen two non-zero digits are significant.

eg. 2003 has 4 significant figures , 50.302 has 5 significant figures.

3. A change of unit of a physical quantity does not change the significant figures .

eg. 223 cm has 3 significant figures, if we change this length in meters we get 2.23 m, which also has 3 significant figures.

4.For a number which have decimal, the starting zeroes are not significant.

eg. 0.0036 has 2 significant figures, 0.526 has 3 significant figures.

5. For a number which does not have decimal, the trailing zeroes are not significant.

eg. 569000 has 3 significant figures.

6. The trailing zeroes with decimal are significant.

eg. 4230.00 has 6 significant figures.