In MathPrint mode on your TI-84 Plus calculator, exponents actually look like exponents! There are two ways to square a number. One way is to type a number and press [x2]. The advantage of using this technique is your cursor stays on the base of the Entry line (see the first screen).
Another way of squaring a number is to type a number and press [^] to put the number to the second power. Notice that as soon as you press [^] (caret symbol), the cursor moves up to the exponent position.
Type a number in the exponent position, and the cursor will contain a small right arrow to remind you to press the right-arrow key to bring the cursor back down to the base of the Entry line (see the second screen).
Of course, pressing [^] allows you to put a number to any exponent you would like (including negative exponents and rational exponents). See the first two lines of the last screen. There are two convenient secondary keys to perform commonly used exponential functions. Press [2nd][LOG] to produce the 10x function, and press [2nd][LN] to generate the ex function.
Square roots work in a similar fashion to exponents. Press [2nd][x2] to select a square root and type the expression you would like to evaluate. Notice that the cursor will stay under the radical sign until you press the right-arrow key (see the last line of the third screen).
To enter a root (other than a square root), press [MATH] to access the square root template. Simply type the index and use the right-arrow key to enter the expression you would like to evaluate. Alternatively, save time by typing the index first, access the square root template by pressing [MATH], and then typing the expression. If you have a TI-84, be sure to type the index before accessing the template: