1. **Problem:** Students are classified by gender (male or female), status (regular or irregular), and field of specialization (mathematics, physics, business, or languages). Find all possible classifications and the total number. 2. **Formula:** Use the multiplication principle: If there are $n$ ways to do one thing and $m$ ways to do another, total ways = $n \times m$. 3. **Step 1:** Number of gender options = 2 (male, female). 4. **Step 2:** Number of status options = 2 (regular, irregular). 5. **Step 3:** Number of specialization options = 4 (mathematics, physics, business, languages). 6. **Step 4:** Total classifications = $2 \times 2 \times 4 = 16$. 7. **Explanation:** Each choice is independent, so multiply the number of options at each stage. 8. **Tree diagram:** - Start with gender: male, female - From each gender, branch to status: regular, irregular - From each status, branch to specialization: math, physics, business, languages 9. **Final answer:** There are **16** possible classifications of students.