# How to Calculate Odds

If you are trying to win the lottery or a game of chance, knowing the odds of a winning combination will help you determine your success.

### Instructions

- TIP: For example, to find the number of possible arrangements of a pick four lottery ticket you would find four factorial, or four times three times two times one, which is 24.
- Step 1: Divide the product of the probabilities by the number of arrangements.
- Step 2: Write the odds of an event occurring as a ratio of some number to one. Use your answer to decide if your odds are worth the risk, such as picking those winning numbers or rolling the right combination.
- FACT: In 2002, Jack Whitaker of Scott Depot, West Virginia, became the biggest lottery winner in history after winning $315 million from a $1 lottery ticket.
- Step 3: Find the number of different arrangements for the selections by finding the factorial of the number of selections.
- Step 4: Multiply all the probabilities together, top numbers multiplied by top numbers and bottom numbers multiplied by bottom numbers. This will give you the probability of making selections in exact order.
- TIP: For example, the first number selection on a "pick four" lottery ticket, with number options ranging from one to 99, has a probability of one out of 99.
- Step 5: Determine the probability of each remaining selection. Remember -- for each selection there is one less choice.
- TIP: For example, the second number selection on the lottery ticket has a probability of one out of 98.
- Step 6: Determine the probability of the first selection.