Multiply entire column by value in one cell and fix it.

How do you (other than manually) multiple an entire column by a value in a cell?

For instance, I am trying to multiply column B by the value in cell A1. I know that I can use a copy, paste special, multiply function, but that only uses the value. But I want a sheet to be flexible, so that if the currency or weight (or whatever was in cell A1) were to change, that I have a flexible table, but without having to copy paste.

Any help would be greatly appreciated.

Are you looking for a formula or a macro?

Just any method that I would be able to do that besides manually. Maybe if there was a function or method that I do not know. Like if you copy paste special, multiply, how would you do this by fixing it to a cell, rather than the value in that cell?

In C1 (Output) use formula =$A$1*B1 then autofill down to the last row used