2.  Significant figures are the figures that are known with a degree of certainty.

3.  Well….we have rules….

4.  Digits from 1-9 are always significant. ◦ Example:  739  3 Sig figs  83.61  4 Sig Figs

5.  Zeros between nonzero digits are significant. ◦ Example:  2,304  4 Sig Figs  3.009  4 Sig Figs

6.  Zeros to the right of the decimal and a significant figure are significant. ◦ Example:  2.300  4 Sig Figs  0.470  3 Sig figs

7.  Zeros used for placing the decimal point are not significant. ◦ Example:  0.0082  2 Sig Figs  5400  2 Sig Figs  5400.  4 Sig Figs

8.  When multiplying or dividing, the answer may only show as many significant digits as the multiplied or divided measurement showing the least number of significant digits.  Huh????

9.  319 x 4,206

10.  When adding or subtracting your answer can only show as many decimal places as the measurement having the fewest number of decimal places.  In English please…….

11.  6.813 + 2.9

13.  700,000,000,000,000,000,000,000,000 meters  How big is this number?  Yeah, I don’t have a clue either.  Lets convert this number to scientific notation…

14.  700,000,000,000,000,000,000,000,000 meters  Step 1: Move the decimal point from here ◦ To the right of the first non-zero diget.  Step 2: Count the number of spaces you moved the decimal. ◦ 26 spaces..

15.  7.0  Now rewrite the number with one digit to the left of the decimal and a minimum of one digit to the right of the decimal  Then express the number of places the decimal is moved as an exponent of 10 x 10 26 Coefficient Exponent

17.  Step 1: Move the decimal point from here ◦ To the right of the first non-zero digit.  Step 2: Count the number of spaces you moved the decimal. ◦ 8 spaces

18.  Because the decimal point was moved to the right, the exponent is negative.  Large numbers ◦ Positive exponent  Small numbers ◦ Negative exponent

19.  7.2 x 10 5

20.  3.0 x 10 -4

21.  5.2 x 10 2

22.  4.0001 x 10 -6

24.  Step 1: Multiply the coefficients  Step 2: Add the exponents

28.  Exponents must be the same.

29.  Step 1: Add the coefficients  Step 2: Keep the exponent