Here comes another one

When we got home from school pick-up with the 7 year old half an hour ago, I commented to the girls that the toddler and I had bought a treat at the shops this morning to have as afternoon tea.

"Oooooo, what is it, what is?" the 5 year old enthused.
"Ice-creams," I told her. "Like choc wedges, but a lot cheaper, they were on special. I got two boxes."
"How many in each box?" the 5 year old wanted to know next.
"10, I think," I said as I lifted them out of the freezer.

She furrowed up her brow for a long minute, her lips moving silently.
"That means, if we all have one every day, we'll have enough for 4 days!" she proclaimed triumphantly.
"No," her 7 year old sister demurred, "5 days, E. 20 how many 4's is 5."
The 5 year old shook her head pityingly at her older sister and said, "But what about Daddy? 5 people, so it's 20 how many 5's. That's 4. Isn't it?" she appealed to me.
"Yes, it is," I said faintly, a little bit staggered. This is the child who's joined a prep class that has as its term 1 goal to be able to count to 20. Heaven help me.

The 7 year old, who is also punching way out of her weight in maths, had done some more contemplation. "How much were they, Mum?"
"Oh, a very good price," I told her, "that's why I got them. $7 for the two boxes."
"Hmmm," she said. "That's ... wait ... less than 50 cents ... more than 25 ...about 35 cents an ice cream, I think?"
I nipped over to grab a calculator, punched numbers and said, "Um, yes. It's exactly 35 cents an ice cream, in fact. That was pretty clever maths there, you two!"

The 7 year old grinned. "Maths is easy, Mum."
"Yeah, maths is fun!" declared the 5 year old as she skipped outside to eat her cheap and delicious treat.

I swear I do not know where they get it from.