Calculated numerical results - 1 | Chemistry and the Scientific Method

How many significant figures should be in the answers to the following calculations?

2.31 x 3.5   

28.6 + 215.1  

(156 – 124) x (475.0) 

3.41 x 102 + 7.87 x 10-2    

3.41 x 102 x 7.87 x 10-2    

2.31 x 3.5   ⇒ 2 significant figures

28.6 + 215.1   ⇒ 4 significant figures

(156 – 124) x (475.0) ⇒ 2 significant figures

3.41 x 102 + 7.87 x 10-2 ⇒ 3 significant figures

3.41 x 102 x 7.87 x 10-2 ⇒ 3 significant figures