Warm up A son weighs 76 lbs. His father weighs 266 lbs. How many times greater does the father weigh than his son? 3.5 times greater

Using Scientific Notation in Multiplication, Division, Addition and Subtraction Scientists must be able to use very large and very small numbers in mathematical calculations. As a student in this class, you will have to be able to multiply, divide, add and subtract numbers that are written in scientific notation. Here are the rules.

When adding or subtracting numbers in scientific notation, the exponents must be the same.

Adding/Subtracting when Exponents are THE SAME Step 1 - add/subtract the coefficients Step 2 – Bring down the given exponent on the base 10

Step 2 – Bring down exponent : Example 1 (2.56 X 103) + (6.964 X 103) Step 1 - Add: 2.56 + 6.964 = 9.524 Step 2 – Bring down exponent : 9.524 x 103

Step 2 – Bring down exponent: Example 2 (9.49 X 105) – (4.863 X 105) Step 1 - Subtract: 9.49 – 4.863 = 4.627 Step 2 – Bring down exponent: 4.627 x 105

The sum of 5.6 x 103 and 2.4 x 103 is 8.0 x 103 8.0 x 106 8.0 x 10-3 8.53 x 103 The exponents are the same, so add the coefficients.

(8.0 x 103) – (2.0 x 103 ) 6.0 x 10-3 6.0 x 100 6.0 x 103 7.8 x 103

Adding/Subtracting when the Exponents are DIFFERENT When adding or subtracting numbers in scientific notation, the exponents must be the same. If they are different, you must move the decimal so that they will have the same exponent.

Moving the Decimal It does not matter which number you decide to move the decimal on, but remember that in the end both numbers have to have the same exponent on the 10.

Adding/Subtracting when the Exponents are DIFFERENT Step 1 – Rewrite so the exponents are the same Step 2 - add/subtract the coefficient Step 3 – Bring down the given exponent on the base 10 ← moving the decimal to the left 10x gets bigger (add) moving the decimal to the right→ 10x gets smaller (subtract)

Adding With Different Exponents (4.12 x 106) + (3.94 x 104) (412 x 104) + (3.94 x 104) 412 + 3.94 = 415.94 415.94 x 104 Express in proper form: 4.15 x 106

Subtracting With Different Exponents (4.23 x 103) – (9.56 x 102) (42.3 x 102) – (9.56 x 102) 42.3 – 9.56 = 32.74 32.74 x 102 Express in proper form: 3.27 x 103

Example 3 (2.46 X 106) + (3.4 X 103) Step 1 – Rewrite with the same exponents 3.4 X 103  0.0034 X 103+3 New Problem: (2.46 X 106) + (0.0034 X 106) Step 2 – Add coefficients 2.46 + 0.0034 = 2.4634 Step 3 – Bring Down Exponents 2.4634 X 106

Example 4 (5.762 X 103) – (2.65 X 10-1) Step 1 – Rewrite with the same exponents 2.65 X 10-1  0.000265 X 10(-1+4) New Problem : (5.762 X 103) – (0.000265 X 103) Step 2 – Subtract Decimals 5.762 – 0.000265 = 5.762 Step 3 – Bring down exponent 5.762 X 103

(7.0 x 103 ) + (2.0 x 102 ) is 9.0 x 103 9.0 x 105 7.2 x 103 7.2 x 102

(7.8 x 106 ) – (3.5 x 105 ) is 4.3 x 104 4.3 x 1010 7.45 x 106

Adding and Subtracting… The important thing to remember about adding or subtracting is that the exponents must be the same! If the exponents are not the same then it is necessary to change one of the numbers so that both numbers have the same exponential value.

Classwork – Write the problem and the answer Turn in when completed (3.45 x 103) + (6.11 x 103) (4.12 x 106) + (3.94 x 104) (8.96 x 107) – (3.41 x 107) (4.23 x 103) – (9.56 x 102) (3.078 x 1010) ÷ (3.8 x 105) (1.479 x 102) ÷ (5.1 x 10-2) (5.8 x 1010) x (9.7 x 103) (1.5 x 106) x (8.1 x 102)

Adding and Subtracting Numbers in Scientific Notation Created by: Langan, Kansky, Nizam, O’Donnell, and Matos