Picking up a cell as a negative in a formula

Hello I was wondering if any one could help. Im trying to get a formula to work. I have two columns one with the figure 45 and other with 1.62%

Im trying to get this sum to work 100-45 x (1.62%) - 100 = (45.89)

I know this is simple but I cant get a formula to work the same way as the sum.The problem im having is with column with the percentage in. I need to pick it up as a minus but cant seem to do this.