1. How many significant figures do the following numbers have?

a. 956 m

b. 786502000000 g

c. 0.4000021 mol

d. 0.000000620 cd

e. 108.777 km


2. Change the following measurement into 3 significant figures;

a. 950, 000 m ¬¬

b. 12.234 g

c. 0.00401 mol

d. 2.3456 m + 6.98 m

e. 100, 000, 000, 000 light-year