Significant Figures and Order of Magnitude

Techniques in the Mathematics of Physics

Physics is the science of measurement. Numbers obtained by direct measurement are important and are therefore referred to as significant. The order of magnitude of a number is the power of ten that is nearest that number. Determining the order of magnitude of a number is useful when performing an estimate of a calculation involving many large numbers. Solve the following problems and place the answers on a separate sheet of paper.

1.  Determine the number of significant figures (numbers) in the following:

a.153

b.11

c.1001    

d.0.007   

e.1000    

f. 100.      

g.101.6   

h.101.000      

2.   Determine the order of magnitude of the following:

a.1.7 x 10exp4

b.5.1 x 10exp3

c.42  

d.4.99 x 10exp2   

e.5.75 x 10exp-7   

f. 5    

g.6.25 x 10exp18  

h.9.2 x 10exp-31

Answer Key:

Question 1

a.

b.

c.

d.

e.

f.

g.

h.

Question 2

a.

b.

c.

d.

e.

f.

g.

h.