# Ambiguous? "How many odd numbers are BETWEEN 1000 & 9999?"

Discussion in 'Mathematics' started by cuyocksol, Jun 18, 2019.

1. ### cuyocksolNew commenter

I'm new to maths teaching, sorry for such a basic question. Tried Googling it, couldn't find an answer to my query.

In a Pearson revision guide I found a question which I simplify as "How many odd numbers are there between 1000 & 9999" - now as an English teacher I'd say that 'between' clearly means NOT including 1000 & 9999, but the book's answer has included 9999. My instinct is that the question would be clearer if it said "from... to...".

What do you think?

2. ### mistercorzi1New commenter

I think this is a poorly worded question. There is ambiguity . Since Maths is a precise language statements like this are usually appended with "exclusive" or "inclusive" eg "The set of real numbers between a and b inclusive"

3. ### frustumStar commenter

I think most would agree that the question you quote is a little ambiguous. In an exam, I think you can be fairly sure that it would be non-ambiguous, for example by saying "between 1000 and 10000". Mathematicians sometimes use "strictly between", but not usually at school level.

4. ### gainlyEstablished commenter

I'd agree the question is ambiguous and I think either answer i.e. including or excluding 9999 should be accepted. Often it is made clear by stating inclusive or exclusive in the question, but frustum's suggestion is even better.