Why isn't 411 divisible by six?

Answer 1

One obvious way to see that 411 is not divisible by six is to realize that since 6 is an even number, all multiples of 6 will also be even numbers. Since 411 is an odd number, it cannot be a multiple of 6 - hence if you divide it by six you must get a non-zero remainder (in this case a remainder of 3).

Answer 2

Because it leaves a remainder (of 3) when you try.