# Sat Maths Stuff

## Sat Maths Stuff

• Submitted By: KrAt0S
• Date Submitted: 08/07/2013 2:56 AM
• Category: Miscellaneous
• Words: 308
• Page: 2
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Math Stuff
Although this guide is for the SAT Subject test in Physics, you’ll need to know quite a bit
of math. If you’re thinking that you’ll just use your calculator to do the math, don’t forget
that calculators are not allowed on the SAT Subject Physics test . Here is a summary of
the really important math facts and formulas.
Exponents
xa · xb = xa+b
(xa)b = xa·b
x0 = 1
xa/xb = xa−b
(xy)a = xa · ya
√xy = √x · √y
1/xb = x−b
(−1)n =

+1, if n is even;
−1, if n is odd.
Scientific Notation
Scientific notation is a short-hand form to write numbers which would have a lot of zeros
when written as decimals. For example, instead of writing 1230000, you can just write
1.23 × 1000000, or 1.23 × 106. The familiar powers of ten include:
10−3 = 0.001, 10−2 = 0.01, 10−1 = 0.1, 100 = 1, 101 = 10, 102 = 100, 103 = 1000.
To go from scientific notation to a plain decimal number, move the decimal to the right
or left according to the sign of the exponent, putting a zero down when you have no other
digits there. For example, for 3.7 × 1012, move the decimal right 12 places and add 11
zeros. Move the decimal to the left for a negative exponent.
37
11 zeros z }| {
00000000000 . = 3.7 × 1012
. |00000{z00000}
10 zeros
23 = 2.3 × 10−11
To go from a plain decimal number to scientific notation, just move the decimal to the
right or left (counting how many places you move) until there is only one digit to the left
of the decimal point, then add “ ×10n ” where n is the number of places you moved the
decimal point (positive if you went left and negative if you went right).