Solve the Equation: Finding the Missing Digit in 20?1=20

To solve this problem, we need to identify which mathematical operation correctly completes the equation $20?1=20$. We will examine each of the basic arithmetic operations to see which one fits:

• Addition ($+$): If we replace the question mark with a plus sign, we get $20 + 1$. This equals 21, which does not match 20. Therefore, addition is not the correct operation.

• Subtraction ($-$): If we replace the question mark with a minus sign, we get $20 - 1$. This equals 19, which does not match 20. Therefore, subtraction is not the correct operation.

• Multiplication ($x$): If we replace the question mark with a multiplication sign, we get $20 \times 1$. This equals 20, which matches the right side of the equation. Therefore, multiplication is the correct operation.

After trying out all the possible choices, we confirm that multiplication is the correct choice. Therefore, the solution to the problem is that the operation to complete the equation $20?1=20$ is $x$.