<p>Here are the answers as best as I can explain them: </p>
<p>Do you know what perimeter is?</p>
<p>Perimeter is the length of the sides of an object. More informally, the perimeter of your house would be how much fence it would take to go all the way around your house. The perimeter of a square is the lengths of all the sides added together. </p>
<p>Do you know what I prime number is?</p>
<p>A prime number is a number that can only be divided evenly by itself and one. 5 is a prime number. Divide 5 by 3 and you get a decimal. 6 is not a prime number. You can divide 6 by 3 and get 2. We would say that the factors of 6 are 3 and 2. </p>
<p>Is -2 a root of 4?</p>
<p>A "root" is a number that can be multiplied by itself a certain number of times to produce a given number. For example, 2 is a square root of 4. Because 2 can be multiplied by itself once (called squaring) to produce 4. -2 is a root of 4 because it can be multiplied by itself to produce 4. </p>
<p>Roots are sometimes represented as an exponent. </p>
<p>x^2 means x * x</p>
<p>and likewise, </p>
<p>x^(1/2) means (the number that can be multiplied by itself to produce x)</p>
<p>so 36^(1/2) = 6, and 6^2 = 36</p>
<p>Roots are often represented as exponents</p>
<p>Do you know how to evaluate (a + b)(a - b)?</p>
<p>This is a rule called "the distributive property". To multiply a + b and a - b, you have to add a(a - b) and b(a - b). Which gives you a^2 - b^2. </p>
<p>If you have (x - 2)(x + 5), you multiply together the two first values (x and x), and add that to -2 * 5, and then add -2 * x and 5 * x. </p>
<p>Do you know how to calculate the area and circumference of a circle? </p>
<p>The circumference of a circle is 2 * pi * radius. Pi is a NUMBER. Pi is a number that we call pi because its decimals never, ever, ever, ever, end. Its approximately 3.1457. Usually on the SAT they won't want you to use 3.14, and they'll want you to use pi, and just put pi in the answer. </p>
<p>The area of a circle is pi * r * r. r is the radius of the circle. </p>
<p>The diameter is just twice the radius. </p>
<p>If anyone has any questions on the above rules, don't hesitate to ask. IMO those rules are key to doing well on the SAT math.</p>