Significant figures

Question

Carry out each ealeulation and give the answer using the proper number of significant figures.

a. 15.90*3.4=

b. 113.5 * 22 =

Answer 1

a) 54 b) 2500

punch them into a calculator but then round them off to nearest 2 digits

2497 becomes 2500 as you only want 2 digits and the rest zeros.

54.06 becomes 54.00 or 54

Answer 2

When you multiply two numbers you report your answer according to the number with the least significant figures.

a) 15.90 * 3.4, use 3.4 it has only 2 significant figures while 15.90 has 4 significant figures

your answer will be 54, that is 2 significant figures

b) 113.5 * 22 again 2 is the least amount of significant figures in this situation so

your answer will be 2500, you round the answer up, and trailing zeros do not count as significant figures unless they are after a decimal point or unless there is a decimal point placed specifically after it.