Solve the Multiplication Problem: 1×4×5 Step-by-Step

To solve this problem, we will use the properties of multiplication.

• Step 1: Recognize that multiplying by 1 leaves the number unchanged. Hence, $1 \times 4$ simplifies directly to 4.

• Step 2: Multiply the result from Step 1 by the remaining number. Thus, $4 \times 5 = 20$.

After completing the steps, we observe that the final result of the calculation is $20$.

Therefore, the solution to the problem is $\mathbf{20}$.