11 Plus Exams Forum

Merchant Taylors Maths 2008

Does 0 count as an even number?

Thanks DG

I was taught that zero is an even number because when divided by 2 the result is a whole number. But then again when I was at school a billion had 12 zeros so who knows what else has changed

What I read in my school days: Zero is an even number.

A number is an even number when divided by 2 results as a whole number. TRUE
Some can also state: the number when added 1 should be an odd number. TRUE

A tutor should not need to ask this question.

My feeling is this is another one of those frustratingly ambiguous questions that seem to crop up in some 11+ papers which our kids are expected to muddle through and get to the "right answer". Is this meant to be a discussion question for a 10 year old? Surely

if odd and even are defined over positive integers then 2 is the first even,
if odd and even are defined over natural numbers then 2 is the first even,
if odd and even are defined over 0 and the natural numbers then 0 is the first even,
if odd and even are defined over all integers then minus infinity is the eight even number.

nyr

I would have said 0 was not an even number.I would have said the 8th even number was 16. Seems I am in a minority.

nyr wrote:(...) if odd and even are defined over all integers then minus infinity is the eight even number. nyr

I am now totally confused! And yes, it is a somewhat ambigous question...

Zero is even. The smallest even is minus infinity but that's almost certainly not the expected correct answer so it comes down to the child having to guess what the examiner was thinking. Should they assume the examiner started from 0 or 1? There is a 50% chance of getting it wrong.

nyr

Infinity isn't a number though.

What about -63797268368746769876576576476? Or just -2? These are even.

Where should one start?

Assuming the examiner wasn't considering negatives, that still leaves the question of whether to start from 0 or 1.