Granted, I'm no mathematician, but... If we have a limit of 2^64 for $x, can't we set $y = representive of multiples of $x's upper limit? $y = 5 = 5x2^64 Wha

Granted, I'm no mathematician, but... If we have a limit of 2^64 for $x, can't we set $y = representive of multiples of $x's upper limit? $y = 5 = 5x2^64 What's the reason for not being able to sub-divide numbers and operations into smaller, more manageable forms?