Purpose Before Classification
Before you ask classification questions such as "What are whole numbers?", you should establish why we classify numbers with questions like "Why do we classify numbers?".
You could then review different ways of classifying numbers and conclude on why one way is better than the others.
One of the problems of learning maths is that we are often taught from a position of authority with the assumption that we should accept facts on face value. Even if this has to be done as the simplest way of making progress, we should be told that this is the process we are following. We should then be directed to where we can find the deeper knowledge.
Also, the exercise should have a place where we can comment on it - such as a link to the comments and feedback.