17698_24_ndx_p599-616_cx.qxd 6/30/06 10:45 AM Page I-13 APPENDIX 4 Scientific Notation A4.1 Multiplying and Dividing Numbers in Scientific Notation Most scientific calculators will multiply and divide numbers in scientific notation; however, it is important to understand what is happening. To multiply numbers expressed in scientific notation, multiply the decimal parts of the number and add the exponents: (A 10n) (B 10m) (A B) 10nm To divide numbers in scientific notation, divide the decimal parts and subtract the exponents: (A 10n)/(B 10m) (A/B) 10nm EXAMPLE A4.1 Multiplying Numbers Expressed in Scientific Notation (1.5 103) (3.8 105) (1.5 3.8) 1035 5.7 108 3 5 (1.2 10 ) (5.3 10 ) (1.2 5.3) 103(5) 6.4 102 YO U R T U R N Multiplying Numbers Expressed in Scientific Notation (3.1 108) (2.8 104) Answer: 8.7 1012 S-1 17698_24_ndx_p599-616_cx.qxd S-2 APPENDIX 4 6/30/06 10:45 AM Page I-14 Scientific Notation EXAMPLE A4.2 Dividing Numbers Expressed in Scientific Notation (5.2 103)/(2.8 105) (5.2/2.8) 103(5) 1.9 108 (1.5 103)/(3.8 105) (1.5/3.8) 1035 0.39 102 3.9 103 YO U R T U R N Dividing Numbers Expressed in Scientific Notation (3.1 108)/(2.8 104) Answer: 1.1 104 A4.2 Adding and Subtracting Numbers in Scientific Notation To add or subtract numbers in scientific notation, first express each quantity with the same exponent, then add or subtract the decimal parts and leave the exponent unchanged. (A 10n) (B 10n) (A B) 10n (A 10n) (B 10n) (A B) 10n EXAMPLE A4.3 Adding Numbers Expressed in Scientific Notation (3.0 104) (2.60 105) (3.0 104) (26.0 104) (3.0 26.0) 104 29.0 104 2.90 105 YO U R T U R N Subtracting Numbers Expressed in Scientific Notation (3.1 107) (2.0 106) Answer: 2.9 107