Generally I run my own numbers

but I was too frustrated when I saw the numbers I just went with what I was told. We got a number from the chain of command that if you were at this much it would cut that much in a format of different amounts. Kinda take your figure to what you make and follow the line this is the new amount they will be taking out.
But I got this email and went back,
I took the old pay times the 4.2 we were paying
took the current pay X the 1.7% raise then used that new pay X the 6.2 we will be paying
…. did I do this right so far?

My different is an increase of just over 60 for the entire month…. How did I mess up or how did they get the 400 number… maybe they can not do math.
And this is why I should know better than to use follow the line math of other people.