4 ms·

Negative numbers work just fine for directions. -3 feet west makes plenty of sense, even if -3 oranges doesn't.

• mc32 5y ago
  Negative numbers work fine for bookkeeping too. You owe someone 3 oranges.
  • agumonkey 5y ago
    it seems there's a little issue in math, in that the concept and notation often assume enough intuition and imagination from the reader -3 looks odd if you interpret it as material existence but as you say, read in bookkeeping context, it's totally natural (npi). it's a bit like numbers 10 is actually 10 (base 10) but we elude it
    • jobigoud 5y ago
      > 10 (base 10) Even this notation assumes base ten for the number written inside the parenthesis. Otherwise it works for any base.
      • mc32 5y ago
        So 10 (base ten).
  • tonyedgecombe 5y ago
    On the other hand double entry was invented so bookkeepers didn't need to deal with negative numbers.
• mcguire 5y ago
  That's one of those metaphors plus what you have been taught about how negative numbers work. It's a product of Cartesian geometry (which had to be invented).