440 pistons

I will try to remeasure mine.
Maybe I made a mistake = I had two
23 month old Grandkids with me.

I am confused:
A 1/2 inch stroker with a 1.5 Comp. deck
would be about Zero deck with a 7.1 Rod
according to what I calculated in a 440 block.

Can someone check my math and help me out?