Define the event or outcome you want to evaluate
Identify the total number of possible outcomes
Identify the number of favorable outcomes
Use the formula: Probability = Favorable outcomes / Total outcomes
Simplify the fraction if possible
Convert the fraction to a decimal if needed
Convert the decimal to a percentage if needed
Check that the probability is between 0 and 1
Verify that all outcomes are equally likely
Recalculate if the sample space changes