We think in different mathematical bases, this was so 'confusing' that hardware creators actually switched to normal base 10 instead of base 8 for size definitions ... (and they could ofc sell you smaller hard-disks for the same price)
so if we talk about 1GB we're talking about 1024 MB and the normal consumer about 1000MB
Functional programming and Object Oriented Programming are isomorphic, which means they can substitute each other completely.