Click here to purchase the entire book in PDF format. Exponents An exponent is just a lazy way to write down that you want to multiply a number by itself. If I say $10^{2}$, then this is just a short notation for ``10 multiplied by itself 2 times'' - therefore, it's $10*10 = 100$. For example, $3^{4} = 3*3*3*3 = 81$. Sometime's you'll see a negative number as the exponent. This simply means that you have to include a little division in your calculation. Whenever you see a negative exponent, you just have to divide 1 by the same thing without the negative sign. For example, $10^{-2} = \frac{1}{10^{2}}$