CP Algebra I Homework: ________________________________________ 7.2 & 7.4 Scientific Notation Objectives: To write numbers in scientific notation; to re-write scientific notation to number form To order numbers written in scientific notation; to multiply numbers written in scientific notation ; to divide numbers in scientific notation Writing Numbers in Scientific Notation Example 1) 267,000 Step 1: Determine where the decimal point is in the number Step 2: Determine where would you put the decimal to make this number be between 1 and 10 Step 3: Decide how many decimal places you need to move the decimal Step 4: Write the new decimal × 10𝑛 , 𝑛 = # of places* *Note: + if the original number is more than 1, the exponent is positive - if the original number is less than 1, the exponent is negative Example 2) 4,605,000 Example 3) 0.0000325 Example 4) 0.00000009 Quick Check: a) 678,000 b) 0.00000435 c) 43,567,800 Rewriting Scientific Notation in “Number Form” (or Standard Form) Step 1: Move the decimal point to the right for positive exponents of 10. 104 Move the decimal point to the left for negative exponents of 10. The exponent tells you how many places to move. Step 2: Fill in with zeros Example 6) 5.07 × 104 10−6 Example 7) 5.6 × 10−4 Example 5) 3.2 × Example 8) 8.3 × Quick Check: d) 4.567 × 105 e) 6.7893 × 10−3 f) 2.45 × 10−5 Using Scientific Notation to Order Numbers Step 1: Write every number in correct scientific notation Step 2: Order each by exponent first and then by coefficient Example 9) Order the numbers from least to greatest: 52 × 104 , 512 × 103 , 5.32 × 102 , 534 Quick Check: Order the numbers from least to greatest: 60.2 × 10−5, 63 × 104 , 0.067 × 103 , 61 × 10−2 Multiplying a Number in Scientific Notation Step 1: Multiply the number times the coefficient Step 2: Simplify so that the number is written in correct scientific notation Example 10) 2.5(6 × 103 ) Example 11) 5(2 × 10−5 ) Quick Check: g) 4.2(3 × 10−4 ) h) 5.3(3 × 105 ) Multiplying with Scientific Notation You can use the property for multiplying powers with the same base to multiply two numbers written in scientific notation. Step 1: Multiply the coefficients Step 2: Add the exponents Step 3: Make sure your final answer is written in proper scientific notation Example 12) (6 × 108 )(6 × 10−4 ) 10−5 ) Example 13) (5.6 × 10−3 )(3 × Quick Check: i) (4.5 × 104 )(2.3 × 10−3 ) j) (7.23 × 10−2 )(4 × 105 ) Dividing Numbers in Scientific Notation You can use the property for dividing powers with the same base to divide two numbers written in scientific notation. Step 1: Divide the coefficients Step 2: Subtract the exponents Step 3: Make sure your final answer is written in proper scientific notation 2.6×105 Example 14) 1.3×10−8 4.2×107 Example 15) 7×10−4 Quick Check: 5.6×102 k) 8×10−3 8.1×104 l) 9×10−3