Floor division with negative number

Question

The expression 6 // 4 yields 1, where floor division produces the whole number after dividing a number.

But with a negative number, why do

Answer 1

A useful way to understand why floor division // yields the results it does for negative values is see this as complimenting the modulo, or remainder, % operator.

5/3  is equivalent to 1 remainder 2 

i.e.

5//3 = 1
5%3 = 2

But

-5/3 = -2
-5%3 = 1

Or

-2 + 1/3rd which is -1.6667 (ish)

It can seem strange, but it ensures results such as -2,-2,-2,-1,-1,-1,0,0,0,1,1,1,2,2,2,3,3,3 etc. when generating sequences.