• To write in scientific notation numbers far from zero.• To rewrite in standard notation numbers that are in

scientific notation.• To learn how calculators represent scientific notation.

• Did you know that there are approximately 75,000 genes in each human cell and more than 50 trillion cells in the human body?

• This means there are about 75,000▪50,000,000,000,000 or3,750,000,000,000,000,000 genes in a body.

• We can rewrite each of the number in scientific notation: ▫3,750,000,000,000,000,000 = 3.75 x 1018

A Scientific QuandaryIn Scientific Notation Not in Scientific Notation

3.4 x 105 27 x 104

7.04 x 103 120,000,0006.023 x 1017 42.682 x 1029

8 x 101 4.23 x 126

1.6 x 102 42 x 102

Classify each of these numbers as in scientific notation or not. If a number is not in scientific notation, tell why not.

4.7 x 103 32 x 105 24 x 106

1.107 x 1013 0.28 x 1011

A Scientific QuandaryIn Scientific Notation Not in Scientific Notation

3.4 x 105 27 x 104

7.04 x 103 120,000,0006.023 x 1017 42.682 x 1029

8 x 101 4.23 x 126

1.6 x 102 42 x 102

Define what it means for a number to be in scientific notation.

A Scientific Quandary• Complete steps 3-5.

▫ Place your calculator in scientific notation mode.

▫ Enter the number 5000 on the home screen and press enter. Your calculator displays the number in its form of scientific notation.

• Repeat with each number in step 5. Record your answers in a chart. ▫ 250, ▫ -5,530▫ 14,000▫ 7,000,000▫ 18▫ 470,000

• Step 6▫ In scientific notation, how is

the exponent on the 10 related to the number in standard notation?

▫How are the digits before the 10 related to the number in standard notation?

▫ If a number in standard notation is negative, how does that show up in scientific notation?

Original Scientific

250 2.5 x 102

-5,530 -5.53 x 103

14,000 1.4 x 104

7,000,000 7.0 x 106

18 1.8 x 101

-470,000 -4.7 x 105

•Step 7▫Write a set of instructions for converting

415,000,000 from standard notation to scientific notation.

•Step 8▫Write a set of instruction for converting

6.4 x 105 from scientific notation to standard notation.

Example• Meredith is doing a report on stars and wants

an estimate for the total number of stars in the universe.

• She reads that astronomers estimate that there are at least 125 billion galaxies in the universe.

• An encyclopedia says that the Milky way, Earth’s galaxy, is estimated to contain more than 10 billion stars.

• Estimate the total number of stars in the universe. Give you answer in scientific notation.

•125 billion = 1.25 x 1011

•10 billion = 1.0 x 1010

• (1.25 x 1011)(1.0 x 1010)=(1.25 x 1) x (1011 x 1010)=1.25 x 1021