Fun Fact

• Your stomach has to produce a new layer of mucus every two weeks otherwise it will digest itself

Scientific Notation

• A given number is written as the product of two numbers

» 10000 = 1 x 104

– Numbers greater than ten have positive exponents 123,000,000,000 = 1.23 x 1011

– Numbers less than ten have negative exponents » 0.000 000 007 51 = 7.51×10−9

Practice

• Convert the following to scientific notation

– 3427

– .0473

Significant figures

• Significant Figures-– Include all the digits that are known plus a last

digit that is estimated

Rules for Significant Figures

• 1. Every nonzero digit is significant– 24.7 714 Each have three sig. figs.

• 2. Zeros between non-zeros are significant – Example: 7003 (four sig. figs.)

• 3. Zeros in front of nonzero number is not significant – Example: .0071 (two sig. figs.)

Rules for Significant Figures

• 4. Zeros at the end of a number to the right of the decimal are always significant – Example: 43.00 (four sig. figs.)

• 5. Zeros at the rightmost end of a measurement with no numbers to the right of the decimal are not significant – Example: 7,000 (one sig. fig.)