Teacher: “If I give you two rabbits and two rabbits and another two rabbits, how many rabbits have you got?” Boy: “Seven!” Teacher: “No, listen carefully again. If I give you two rabbits and two rabbits and another two rabbits, how many rabbits have you got?” Boy: “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?” Boy: “Six.” Teacher: “Good. Now if I give you two rabbits and two rabbits and another two rabbits, how many rabbits have you got?” Boy: “Seven!” Teacher: “How on earth do you work out that three lots of two rabbits is seven?” Boy: “I’ve already got one rabbit at home now!”