Rules in Counting and Solving with Significant Figures

Nonzero Digits

• every nonzero digit is significant

  • 24 = 2 SF

  • 3.56 = 3 SF

  • 7 = 1 SF

Sandwiches O’s

• zero’s between non-zeros are significant

  • 7003 = 4 SF

  • 40.9 = 3 SF

Leading O’s

• zeros appearing in front of non-zero digits are not significant

• act as placeholders

• cant’ be dropped, show magnitude

  • 0.00024 = 2 SF

  • 0.453 = 3 SF

Trailing O’s to the right of a decimal point

• zero’s at the end of a number and to the right of a decimal point are significant

  • 43.00 = 4 SF

  • 1.010 = 4 SF

  • 1.50 = 3 SF

Trailing O’s to the left of a decimal point

• zeros at the end of a number and to the left of a decimal point are not significant

  • 300 = 1 SF

  • 27,300 = 3 SF