What is 45 × 0.1?

The answer to 45 × 0.1 is 4.5.

To explain, multiplying a number by 0.1 is the same as finding 10% of that number. So, when you take 10% of 45, you get 4.5. This works because 0.1 is equivalent to 1/10, and dividing 45 by 10 gives you the same result. If you have any more questions or need further assistance, feel free to ask!