Scientific Notation• Number expressed as:

– Product of a number between 1 and 10 AND a power of 10• 5.63 x 104, meaning • 5.63 x 10 x 10 x 10 x 10 • or 5.63 x 10,000• or 56,300

– ALWAYS have only ONE nonzero digit to the left of the decimal point

– ONLY significant numbers are used in the first number– First number can be positive or negative– Power of 10 can be positive or negative

When to Use Scientific Notation

• Astronomically Large Numbers– mass of planets, distance between

stars, number of atoms

• Infinitesimally Small Numbers– size of atoms, protons, electrons,

distance between atoms

• A number with “ambiguous” zeros– 59,000 has two sig. figs.– 5.9 x 104

Converting From Standard to Scientific Notation

• Move decimal until it is behind the first sig fig• Power of 10 is the # of spaces the decimal moved• Decimal moves to the left, the exponent is positive• Decimal moves to the right, the exponent is negative

– 428.5 4.285 x 102

(decimal moves 2 spots left)

– 0.0004285 4.285 x 10-4

(decimal moves 4 spots right)

Online Resources

• Nice web page on metric system

• Practice converting to scientific notation