2. Significant Figures and Scientific Notation Significant Figures:Digits that are the result of careful measurement. 1.All non-zero digits are considered to be significant e.g. 189.57 has 5 significant figures. 2.All zeros between non-zero digits are significant. e.g. 505 has 3 significant figures. 3.Trailing zeros to the right of a decimal point are significant. e.g. 6.000 has 4 significant figures. 4.Leading zeros to the left of the first non-zero digit are not significant. e.g. 0.00248 has 3 significant figures.

3. Scientific Notation e.g.: a) 29.= 2.9 x 10 1 b) 0.052 = 5.2 x 10 -2 c) 5300 = 5.3 x 10 3 d) 29 979 280 000. = 2.9979280000 x 10 10 Adding/ Subtracting measured quantities: e.g.: 1) 14.6 5 + 256.5 + 0.6 45 271.7 95 Least precise Round to 1 decimal place 0 to 4stays the same 5 to 9round up *exactly 5 round to even number = 271.8

4. e.g.: 2) 76 - 56.7 19.3 Least precise Round to 0 decimal places 0 to 4stays the same 5 to 9round up *exactly 5 round to even number =19

5. Multiplication/ Division measured quantities: e.g. 1)400 / 30 000 = 1.3 x 10 -2 The answer should be expressed with the same significant figures as the # in the question with the least number of significant figures. (Calculator) = 1 x 10 -2 (Sig Fig) e.g. 2)3.21 x 10 4 x 4.32 x 10 -3 x 6.5 x 10 8 4.11 x 10 -6 = 2.19311 x 10 16 (Calculator) = 2.2 x 10 16 (Sig Fig)

6. Classwork: Classwork: Scientific Notation worksheet Scientific Notation worksheet Measuring worksheet Measuring worksheet Homework: Homework: Finish Measuring worksheet Finish Measuring worksheet