Lesson 1-3b

Significant Figures

Page 19 - 21

What We’ll Learn Today

• Significant Figures• Significant Figures in standard notation• Why significant figures are EASY

(Cheezy Lemon Squeezy) to identify when using scientific notation

What a Significant Figure Is and Is Not

• Significant figures are all the digits in a number that were measured with a balance, ruler or graduated cylinder

• Significant figures are not zeros that are needed as place holders when writing a number in standard notation

Standard Notation: Significant Figures can be a little tricky

• All digits 1-9

• Any zero in between two 1-9 numbers

• If a zero does not “need” to be there, but is added to the end of a number, it is significant because it was measured.

• Zeros are not significantif they are “needed” to show the proper place value for other numbers

Significant Digits for Numbers in Scientific Notation

• All digits before the “” are significant figures!

3.560 x 104 = 4 significant digits

1.23 x 102 = ____ significant digits

4.7800 x 109 = ____ significant digits

45.34 x 105 = ____ significant digits