Powers

If you have an exponent to an exponent, multiply the exponents together:

--->   (5⁴)²  =  5^{4 x 2}  =  5⁸

You can think of it this way:  the first exponent (the 4) tells you how many 5's you have in each group; the second exponent (the 2) tells you that you have 2 groups. When you have 2 groups with 4 in each group, you have 2 x 4 or 8 items; in this case, you have eight 5's multiplied together.