1. The problem is to understand how to input mathematical expressions into a calculator correctly. 2. Calculators require expressions to be entered using standard mathematical notation: use parentheses for grouping, operators like +, -, *, / for addition, subtraction, multiplication, and division respectively. 3. For example, to calculate $2 + 3 \times 4$, you can enter it directly as 2 + 3 * 4, and the calculator will follow the order of operations (multiplication before addition). 4. If you want to change the order, use parentheses: $(2 + 3) \times 4$ means add 2 and 3 first, then multiply by 4. 5. For powers, use the caret symbol ^, e.g., $5^2$ is entered as 5 ^ 2. 6. For square roots, use the square root function or enter as $\sqrt{9}$. 7. Always check your calculator’s manual for specific syntax, but these rules apply to most scientific calculators. 8. Practice entering simple expressions and verify results to become comfortable.