1. Enter Values:
   • Enter n: In the “Enter n (Total items)” field, input the total number of items.
   • Enter r: In the “Enter r (Items chosen)” field, input the number of items you’re choosing from the total. Ensure that n is greater than or equal to r for valid results.
2. Calculate:
   • Click the Calculate button to display the results.
   • The calculator will show both:
     • Permutation (P(n, r)): The number of ways to arrange r items out of n items where the order matters.
     • Combination (C(n, r)): The number of ways to choose r items out of n items where the order doesn’t matter.
3. Reset:
   • Click the Reset button to clear both the input and output fields.
   • The calculator will reset, allowing you to enter new values without refreshing the page.

This tool provides quick calculations for permutation and combination, useful for statistics, probability, and combinatorics tasks.