Transcript Scientific Notation - St. Anne Catholic School

Scientific Notation
Basics
• All numbers written in scientific notation will look
like this:
n x 10a
n = a number that is greater than or equal to one and less
than 10
1 ≤ n < 10
a = the number of times the decimal moved when the
number was in standard form. The number in standard
form determines whether the exponent is positive or
negative.
Positive Exponent
• The exponent will be positive if the number in
standard form is greater than 1.
• Example:
549.3
This is a number greater than 1. To
write this in scientific notation, move the decimal point two (2) times
to the left to make a number less than 10 but greater than or equal
to 1.
5.493
5.493 X 102
Now the power of 10 that goes with this number will have a positive
exponent of 2 because we moved the decimal two times and the
number was greater than 1 in standard form.
Negative Exponent
• The exponent will be negative if the number in standard
form is less than 1.
• Example: .000298
This is a number that is less than 1. To
write this in scientific notation move the decimal four (4) times to the
right in order to get a number less than 10 and greater than or equal
to 1.
2.98
2.98 x 10-4
The power of 10 that goes with this number will have a negative
exponent because the number in standard form was less than 1.
Practice Problems
•
Write the following numbers in scientific notation.
1.
12.9
2.
999
3.
.000007
4.
.056
5.
18
6.
.000288
•
Write the following numbers back in standard form.
1.
4.3 x 10-3
2.
9.825 x 102
3.
5.04 x 10-1
4.
1.0001 x 105
5.
3.77 x 10-4
6.
8.1 x 103