You naturally assume the 2nd to last total is 4990 and are adding 10 to make 5000, but in reality the total is only 4,090...which when 10 is added to equals 4100.
Actually it's prolly more like you assume that total is 4900, and when it says to add 10, you think of 100. It's just tricky to visualize that zero sometimes.
[FONT=Palatino Linotype]"Bust a nut!" - Dimebag
"Imagination is more important than knowledge." - Einstein[/FONT]
"Imagination is more important than knowledge." - Einstein[/FONT]