Counting And Discounting

(I’m a cashier at a place that sells small items of furniture, storage containers, and so on. We are having a 10% off sale. My last customer caused a huge amount of trouble due to getting angry and shouting over not understanding the difference between 10% and $10, so I’m feeling frazzled. A mother and her child, probably seven or eight, come up to my register and start unloading their items while they talk.)

Mother: *to the kid* “Now, this container was $19.95, but we bought two, so how much is that?”

Kid: “$39.90!”

Mother: “Well done! But remember, there’s 10% off today. What’s 10% of $39.90?”

Kid: “$3.99, so the real price would be… umm, $35.91?”

Mother: “That’s right! Nicely done! But now here comes the hard one, so look out! I have my membership card!”

(The child’s eyes widen. Membership cards give a further 25% discount.)

Kid: “Okay, okay, umm…”

Mother: “You can do it!”

(By this time, I’ve scanned the items and bagged them. Just as I’m about to say the total, the child beats me to it.)

Kid: “$26.93!”

Mother: “Fantastic job! I think we get to stop at the playground on the way home!”

Kid: “Yes!” *jumps up and down gleefully*

(After my last customer, a fully grown man who couldn’t understand what a percentage was, I’m literally dumbfounded. In the end, I call my manager and we give the mother a further employee discount, which her child also worked out.)