Today’s lesson . . .
What:
Scientific Notation with
Negative exponents
Why?
How?
How do you write a
DECIMAL number in
scientific notation
(provide example) ?
What is the difference
between positive and
negative exponents
(when used in scientific
notation)?
What do you remember from last class ?
LARGE
multiplication
ten (10)
power
Example: 2.5 x 10-5
What about negative exponents ??
This is today’s focus!!
small
To convert From scientific notation to a “regular #” . . .
There are TWO STEPS:
1) Locate the exponent– which tells you how many places to move decimal.
2) Move decimal to the LEFT (exponent is the # of jumps), and add zeros in front as
needed.
For example:
2.95 x 10 -5 = ____________
As soon as you see a
NEGATIVE EXPONENT,
think DECIMAL # !!
Follow the above two steps. Since there is one digit to the left of the decimal already, we
will need to add FOUR EXTRA ZEROS IN FRONT of the number– this makes 5 jumps
total!
Answer: 0.0000295
We need 3 zeros in FRONT!
0.00028
0.000009
We need 6 zeros in FRONT!
0.000000405
0.0000702
How do you write a decimal number in scientific notation ?
As soon as you see a DECIMAL
number, think NEGATIVE
EXPONENT!!!!
There are TWO STEPS:
1) Locate the decimal.
2) Move decimal until you make a number greater than 1, but less than 10 (# of
“jumps” is the exponent number, but remember to add a negative sign)!
For example:
0.00032 = ____________
Follow the above two steps. We need to “jump” the decimal point FOUR PLACES
to the right in order to make a decimal greater than 1, but less than 10!
Answer: 3.2 x 10 -4
3.4 x 10-5
1.02 x 10-4
5 jumps!
4.05 x 10-3
7 x 10-6
6 jumps!
Mixed practice:
2.5 x 108
36,000
7.5 x 10-7
90,040,000
2.09 x 10-3
0.0000059
5.723 x 109
As soon as you see a DECIMAL
number, think NEGATIVE
EXPONENT!!!!
0.0072
Wrap-it-up (summary):
Provide an example of a number written in scientific notation (with a
negative exponent) and give the answer.
Explain the difference between scientific notation with positive exponents
and scientific notation with negative exponents.
END OF LESSON