1. **Restate the fifth point:** We need to calculate $3!$, which is the factorial of 3. 2. **Definition of factorial:** The factorial of a positive integer $n$, denoted $n!$, is the product of all positive integers from 1 up to $n$. 3. **Formula:** $$3! = 3 \times 2 \times 1$$ 4. **Calculate step-by-step:** - Multiply 3 by 2 to get 6. - Multiply the result by 1, which keeps it 6. 5. **Result:** $$3! = 6$$ 6. **Explanation:** Factorials are used in combinations and permutations to count the number of ways to arrange or select items. Here, $3!$ is the number of ways to arrange 3 items, which is important for simplifying the binomial coefficient formula.