I just found out about this debate and it's patently absurd. The ISO 80000-2 standard defines ℕ as including 0 and it's foundational in basically all of mathematics and computer science. Excluding 0 is a fringe position and shouldn't be taken seriously.
the standard (set theoretic) construction of the natural numbers starts with 0 (the empty set) and then builds up the other numbers from there. so to me it seems “natural” to include it in the set of natural numbers.
Counterpoint: if you say you have a number of things, you have at least two things, so maybe 1 is not a number either. (I'm going to run away and hide now)
I'd learned somewhere along the line that Natural numbers (that is, the set ℕ) are all the positive integers and zero. Without zero, I was told this were the Whole numbers. I see on wikipedia (as I was digging up that Unicode symbol) that this is contested now. Seems very silly.
I like how whenever there's a pedantic viral math "problem" half of the replies are just worshiping one answer blindly because that's how their school happened to teach it.
As a programmer, I'm ashamed to admit that the correct answer is no. If zero was natural we wouldn't have needed 10s of thousands of years to invent it.
Other fun arguments in the same vein:
Is atheism a religion?
Is not playing golf a sport?
For extra fun, try explaining the answers to both in a non-contradictory way.
Zero grew up from the seeds of the undefined, just like negative numbers and people who refuse to accept that the square root only has one value. Undefined is a pathway to many abilities some would consider unnatural.
When you count upwards you start from 1, and go up. However, when you count down you usually end on 0. Surely this means 0 satisfies the definition.
The natural numbers are derived, according to Brouwer, from our intuition of time of time by the way. From this notion, 0 is no strange idea since it marks the moment our intuition first begins _
So 0 is hard. But you know what? Tell me what none-whole number follows right after or before 0. That's right, we don't even have a thing to call that number.