A number combination calculator determines the number of possible combinations of a smaller set of numbers from a larger set of numbers. Most graphing calculators have built-in functions to solve for this number. Additionally, several combination calculators are available online at CalculatorSoup.com, StatisticsHowTo.com and MathIsFun.com.
A combination refers to a selection of numbers from a larger set of numbers in which the order of the individual numbers of the set does not matter. A combination can be calculated by hand using the formula n! / (r! (n - r)! ), where n represents the total of numbers present in the larger set and r represents the number of values in the smaller set.
Similar to combinations are permutations. Permutations are combinations in which the order of the individual numbers of the smaller set is significant. Because the order of the numbers matters, permutation calculations generate larger figures than combination calculations.