Scientific Notation Extremely Large and Small Numbers Large and small numbers are prevalent in Standard Form or our world: Decimal Form In 2011 the Use National Debt was: $15,143,572,733,215 The mass of a dust particle is approximately: 0.000000000753 kg Scientists have created an easier way to express these extreme numbers. Introduction to Scientific Notation: Powers of Ten Decimal form Powers of 10 1,000,000,000 109 1,000,000 106 1,000 103 10 101 1 100 0.1 10-1 0.001 10-3 0.000001 10-6 Name One billion One million One thousand Ten One One tenth One thousandth One millionth Scientific Notation is based on Powers of Ten. Definition of Scientific Notation Numbers in Scientific Notation are written as: c x 10n where c is a decimal number greater than or equal to 1 and less than 10 (Typically c is rounded to 2 or 3 decimal places) and n is an integer. Below are two 5 examples: 1.2 10 3.5 10 4 Example: Which expression is written in correct Scientific 3.9 is the only number greater than or equal to 1 and less Notation? than 10 AND the exponent is an integer a 13.2 105 b 7.035 1010.2 c 3.9 1012 d 0.45 1020 Converting Standard Form to Scientific Notation By converting the power of 10 to Standard Form Notation, the true value of the Scientific Notation number can be obtained. Example: Convert the following from Standard Form to Scientific Notation . Then try to find a shortcut. 1.2 10 1.2 100000 120000 5 The positive 5 makes the number bigger, by moving the decimal 5 places to the right. 1.2 0 0 0 0. 1 2 3 4 5 3.5 10 3.5 0.0001 0.00035 4 The negative 4 makes the number smaller, by moving the decimal 4 places to the left. 0 .0 0 0 3.5 4 3 2 1 Examples Rewrite each Scientific Notation in Standard Form without a calculator. a. 1.345 10 134,500,000 8 1.3 4 5 0 0 0 0 0. 1 4 3 2 7 6 5 8 9 b. 4.103 10 0 .0 0 0 0 0 0 0 0 4.103 9 8 7 6 5 3 4 2 The – 9 moves the 0.000000004103 decimal 9 places to the left (smaller). 1 5 c. 7.8 10 0.000078 0 .0 0 0 0 7.8 5 4 3 2 1 d. 3.67 10 3,670,000 6 3.6 7 0 0 0 0. 1 2 3 4 5 6 The + 8 moves the decimal 8 places to the right (bigger). The – 5 moves the decimal 5 places to the left (smaller). The + 6 moves the decimal 6 places to the right (bigger). Converting Scientific Notation to Standard Form To convert Standard Form to Scientific Notation, find the largest power of ten such that when it divides the number, the result is between 1 and 10. 10 Example: Convert the following from Scientific Notation to Standard Form. Then try to find a shortcut. 13 15,143,572,733, 215 10,000,000,000,000 1.514 Round to 3 decimal places The number is made smaller by moving the decimal 13 places (power of ten needs is positive) 10-10 0.000000000753 0.0000000001 7.53 The number is made larger by moving the decimal 10 places (power of ten needs is negative) 1.514 10 13 . 15143572733215. 13 12 11 10 9 8 7 6 5 4 3 2 1 7.53 10 10 0.000000000753 . 1 2 3 4 5 6 7 8 9 10 Examples Rewrite each Standard Form in Scientific Notation without a calculator. a. 245000 2.45 10 5 2 .4 5 0 0 0. 5 4 3 2 1 b. 1.78 1.78 Already in Scientific Notation, it is a number greater than or equal to 1 and less than 10 c. 0.000722 7.22 10 0 .0 0 0 7. 2 2 1 2 3 Move the decimal + 5 places to the left (positive since the number is made smaller). 4 4 Move the decimal - 4 places to the right (negative since the number is made bigger). d. 17, 439,502 1.744 10 places to the left (positive 7 Move the decimal + 7 1.7 4 3 9 5 0 2. 7 6 5 4 3 2 1 since the number is made smaller). Arithmetic with Scientific Notation In order to multiply or divide numbers in Scientific Notation, use the properties of exponents. Examples: Simplify the following expressions a. 1.4 10 7.6 10 7 4 3 8 1.4 7.6 10 10 10.64 10 1.064 10 4 3 Regroup b. 1.2 10 Simplify 4.8 10 1.2 4.8 10 10 0.25 10 1 4 1 Regroup 4 3 Simplify Scientific Notation 2.5 10 2 Scientific Notation Scientific Notation and the Calculator Most scientific calculator write in large and small numbers in Scientific Notation. In TI calculators the letter E stands for x10, for example 1.5 E12 = 1.5x10 12 Make sure to rewrite what the calculator displays into correct scientific notation. Examples: Use the calculator to write the following expressions in Scientific Notation. a. 78,000 2, 400,000,000 Calculator: 1.872 E14 1.872 1014 b. 0.000000748 500 Calculator: 1.496 E 9 1.496 109