1. The problem is to calculate the product of 40 and 40. 2. The formula for multiplication is $a \times b = c$, where $a$ and $b$ are numbers and $c$ is their product. 3. Here, $a = 40$ and $b = 40$. 4. Multiply the two numbers: $$40 \times 40 = 1600$$ 5. Therefore, the product of 40 and 40 is 1600.