How to explain that zero is an even number?

[MsPepperminCreams]

My son is in reception and is learning about odd and even numbers. This morning he asked me if zero was odd or even. After looking it up I said it was even, because it's surrounded by minus 1 and 1, and zero divided by 2 is zero...a whole number. He looked at me like I was crazy when I showed him zero slices of toast on the plate!

Anyone got any better suggestions?

I think I'd cheat and say zero is even because it ends in zero, and all numbers ending in zero are even... 10, 20 etc.

I would count in 2s (which he probably knows), explaining that all those numbers are even, and show him the numbers ending in zero. That might help him make the link. Although I'd probably say zero is neither odd or even! Got me thinking now!

What?! 0 is even?
I think you've blown my poor little mind!

I guess it divides by 2.

It divides by everything though, and multiplies by everything- and the answers always the same!!

I think this might be one of those questions where the education is in thinking about the concept rather than reaching an answer.

0 divided by 2 is 0, a whole number.

Also think of it as counting in twos, show it on a number line? 0 fits the even 'pattern'

Proving you are all right. en.wikipedia.org/wiki/Parity_of_zero

I did have to think about it. So my brain has done some work today so I'm going back to my John Grisham now.

I've thought a bit about it now.

Get a load of identical counters, put them in two places. I'd probably put a piece of string down the middle of the table, and put out 2 at a time. then take away one at a time from each pile.

Every time there is the same number of counters in each pile, the total is even.

When there is NOTHING in each pile, the total is still even.

Because nothing is the same as nothing.

Could you say that after every even number comes an odd number? So 0-1-2-3 etc? This theory may not stand true my maths is shit

Read that wiki article, think simplest way of explaining to child is that even numbers are numbers in the 2 times table, and 0x2=0.

I think for this age group it's really hard to explain (I'll post videos for slightly older children). But two means of proving even number with only addition or subtraction>

even number + even number = even number (divisible by 2 - won't know that, but can see 2 groups with same number).

even number - odd number = odd number (not divisible by 2 - won't know that, but can't make 2 equal groups (so two groups with different numbers)).

Lovely video about zero (in terms of marking place - tens, hundreds, thousands here for young children: )

A more complicated video (really KS2 level) from numberphile on zero here - which proves 0 is even:

When I was little I had a book about odd and even numbers where the numbers were represented by people. For even numbers they all had a partner, but for odd ones there was someone left out.
As there's no one left out, xero must be even.

sorry forgot to add you can do odd - even = odd number.

choccypig - now that I've visualised that string down the table, it makes better sense.

Will explain like that if ds asks again.

Woah, my brain can't cope with that Wiki article on a Friday.

Yes yes DeWe I like that analogy, with zero there's no-one left out

try this wiki instead simple.wikipedia.org/wiki/Even_number

Because if you start at zero with your hands on your shoulders and touch either your head or your shoulders alternately as you count each number, all the shoulders are even!

You can't divide by zero, (think of it as you can't put something into no groups there mt best least one group)

Just teach that any even numbers end in 0, 2, 4, 6 or 8, that's all they need to know at that age.

I've just asked DD. she said even because the next number is one which is odd and they follow a pattern of odd then even.

Thank you everyone.

I've printed off a a number line with minus numbers on it, so will show him the odd/even pattern on that. (I didn't learn about minus numbers until secondary school. )

He can count in 2s (and 5s and 10s) and is doing doubling/halving/sharing over the next couple of weeks in class, so I've printed off a multiplication table which includes zeros, so we can look at zeros in general and how zero times/divide by whatever is always zero.

Will try the string idea if he still asks, and I love the videos!