# numbers

#### nandoestudo

##### New member
From these numbers: 45 20 24 36 18 08
Which are odd, and which ones are even?

Staff member

#### HallsofIvy

##### Elite Member
Or- my suspicion- are you using the words "odd" and even in a non-standard way?

#### Subhotosh Khan

##### Super Moderator
Staff member
Or- my suspicion- are you using the words "odd" and even in a non-standard way?
Is there a non-standard way to define odd and even numbers?

#### HallsofIvy

##### Elite Member
Of course. Suppose we say that a number is "even" if and only if it is divisible by 5, "odd" if it is not. That's certainly "non-standard". Or we could say a number is "even" if and only if the sum of its digits is divisible by 9, "odd" otherwise.

Surely you are not asking if there is a standard non-standard definition?

#### Subhotosh Khan

##### Super Moderator
Staff member
Of course. Suppose we say that a number is "even" if and only if it is divisible by 5, "odd" if it is not. That's certainly "non-standard". Or we could say a number is "even" if and only if the sum of its digits is divisible by 9, "odd" otherwise.

Surely you are not asking if there is a standard non-standard definition?
Not being a mathematician (just user), I am kind of suspicious about my own comprehension of definitions. I wish you had used some other term as opposed to "non-standard" (which casts a shadow of "standard"). I think my khan-fusion would have been reduced if you had used terms like "irrelevant personal definition".

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