Complicated Find - Replace

I've attached the file (i think) to make thing easier.

I am trying to get look at the first row of numbers for a part and then place in a corresponding number below. There are some examples already there such as 10 has 910 under it, and 5 has 400 under it.

I was currently playing around with this code:

'Value you want to find

xFind = 5

'Value you want to input

xReplace = 50

    Cells.Find(What:=xFind, After:=ActiveCell, LookIn:=xlFormulas, LookAt:= _

        xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, 

MatchCase:=False _

        , SearchFormat:=False).Activate

    ActiveCell.Offset(-1).Value = xReplace

But i don't know that this is the right direction to take with it and it doesn't seem to want to cooperate with me. Any suggestions?