Teacher: No, listen carefully again. If I give you two rabbits and two rabbits and another two rabbits, how many rabbits have you got?
Paddy: Seven!

Teacher: Let's try this another way. If I give you two apples and two apples and another two apples, how many apples have you got?
Paddy: Six.

Teacher: Good. Now if I give you two rabbits and two rabbits and another two rabbits, how many rabbits have you got?
Paddy: Seven!

Teacher: How on earth do you work out that three lots of two rabbits is seven?
Paddy: I've already got one rabbit at home now!