I'm an English teacher and like to have fun with my form class.
Two year 9 (aged 13) kids were arguing about whether 7x0 equalled 7, 1, 0 or infinity. The whole class was laughing at them. So what should a good teacher do?
I asked - "If you have no 7s how many 7s do you have?" None came the reply.
Then I asked - "If you have 7 zeros how many zeros do you have." Seven came the rely. Ah ... came the enlightened reply.
So 0 x 7 = 0 but 7x0 = 7 came the enlightened shoutback from one of the kids.
The rest of the class sat in stunned silence as they were all rethinking their math skill. I left it at that. Newly enlightened, not. Ha ha.