Hacker News new | ask | show | jobs
by progre 1544 days ago
For addition I can see the binary addition at work. The ding "carries" if it get put in a ring that already has a ding by getting its own ring etc... For multiplication I just WAT
1 comments

Take a couple expanded algebraic representations of base-2 numbers:

1×2 + 1×4 + 0×8 + 1×16, 1×8

and substitute the second for every 1 in the first,

8×2 + 8×4 + 0×8 + 8×16

then finally un-distribute,

(1×8)(1×2 + 1×4 + 0×8 + 1×16)

and that's why putting small copies of the second number in the place of every "ding" in the first number results in multiplication.

Oh yeah, thanks!