Solve Multiplication Equation: Find the Factor in 1 × ? = 100

To solve this problem, we apply the identity property of multiplication:

• Step 1: Recall that any number multiplied by 1 remains the original number. This property is fundamental in arithmetic and states $a \times 1 = a$, where $a$ is any real number.
• Step 2: Apply this property to the problem. Here, $? \times 1 = 100$, which implies that the unknown number must be 100 since multiplying any number by 1 does not change its value.

Therefore, by applying the identity property of multiplication, the solution to our problem is clearly:

$100$