Multiply column by a measure

I have created a new parameter that requires a users input. I need to multiply a whole column by this value. For example if someone types 20 into the box, every entry in the column will be multiplied by 20. I have tried creating a new column using the following. 

New_column= [Parameter]*[Column]

However, the parameter being entered is not being picked up. 

Thanks in advance for the help.