This calculator requires the use of Javascript enabled and capable browsers. This calculator teaches the basics of algebra in setting and determining unknowns. Enter the known and unknown values from your percentage problem. In classic algebraic format, place an x in the box where the value is unknown. Then select Calculate and click on it. The unknown will be replaced by the correct value. The tutor will display the formula and the logic for the problem. You can learn how the equation was derived and calculated from the data in the information box. Another way to easily understand the usage of this calculator is to examine the entry area below. The value (first variable) is this percentage (second variable) of the amount (third variable). Any of the three can be the unknown by placing the x in it and inserting values in the other two. For example, if you wished to know "What is the Value for 10 Percent of the Amount, 500?"; you would place an "x" in the Value box, 10 in the Percentage box, and 500 Amount box and click on Calculate. The answer of 50 would appear in the Value box and the formula would be given in the Formula Information area. The "x" can be in any box in order to determine that information. You must supply the other two values; the "x" must be present in order for the calculator to work. It is an effort to teach new algebra students the "variable" thought process.