Significant Figures
Determine the number of significant figures in each number and write it to the left of the number.
A. ___ 96.7
B. ___ 9.6700
C. ___ 7.0200
D. ___ 0.04010
E. ___ 54.000
F. ___ 70164
G. ___ 0.8000080
H. ___ 90
I. ___ 0.009
J. ___ 50000
Solve the following math problems. First, find the calculator answer. Write the answer in scientific
notation using the correct number of significant figures.
K. 0.03287g \times 45.2g=
L 125.5kg+52.68kg+2.1kg=
M. 0.258g + 0.36105ml=
N. 1250.cal-(234.207cal+52.69cal)=
O. (0.12g+5.16g) \times (93.0g-45.56g)=
Rounding Rules
• If the first digit removed is ? 4, drop it & the following digits
• If the first digit removed is ? 5, round the previous number up
Working Problems by Dimensional Analysis
• Identify known information
• Identify answer type & units
• Identify conversion factors
• Solve—ensure units cancel properly
• Remember that conversion factors can be inverted when necessary.
SI or Metric system practice