10.5 & 10.6 Reading & Writing Scientific Notation --BEFORE you write your new essential question: Tape in Exponents Foldable on the next page then skip 2-3 pages- 10.5 & 10.6 Reading & Writing Scientific Notation Essential Question: How can you read or write numbers in scientific notation?

1.79 x 10 standard form=written as normal # ex. 5,400 scientific notation # written as two factors using power of 10 7 1.79 x 10 A power of 10 A number of 1-9 in front of decimal

Example 1 Tell whether the number is written in scientific notation. Explain. 5.9 × 10 −6 0.9 × 10 8 12 × 10 4 1.285 × 10 7

RULES – Standard Form Scientific Notation. 1 RULES – Standard Form Scientific Notation 1. Always start at the DECIMAL (or imaginary decimal ex. 5 is 5.0) 2. Make scoops from the decimal & Stop when there is only digit of 1-9 to the left of decimal 3. Count the scoops, NOT the zeros, this is your exponent 4. A standard form # less than one, will have a negative exponent 5. A standard form # greater than 9 will have a positive exponent

Example 2: Write the number in scientific notation 57,000 6830 25,000,000 0.00033 0.000506 0.007

Scientific Notation Standard Form positive exponent means move the decimal to the right, negative exponent means move the decimal to the left.

positive exponent move decimal right, negative exponent move decimal left. Write the number in standard notation. 1.35  105 1.35  10 5 10 = 100,000 5 1.35  100,000 135,000 Think: Move the decimal right 5 places.

positive exponent move decimal right, negative exponent move decimal left. Write the number in standard notation. 2.7  10–3 0.0027 Think: Move the decimal left 3 places.

Example 5 Write the following in standard form. 3.22 × 10 −4 7.9 × 10 5 6 × 10 7 9.9 × 10 −5 12.85 × 10 4

Example 6 Order the numbers from least to greatest

Multiply or Divide #’s in Scientific Notation: Divide. (keep base of 10 & subtract exponents) 20.5× 10 −3 5.0× 10 2 Multiply. (keep base of 10 then add exponent) 1.5× 10 −4 ×(6× 10 −3 )