The other day we started "doing school" by reading about our current topic, Ancient Greece. The girls decided they were thirsty after the first book and while SK helped the others make hot chocolate, I started working on making a CD for my dh for Valentine's day (shhh, it's a surprise!) Well, I ran into some technical difficulies and by the time I figured it out, the girls were upstairs playing. I was all set to round them back up and resume learning about Ancient Greece when I overheard them playing store. I peeked in the bedroom and the older 2 each had a store set up with prices, money, and even coupons. "If you buy 4 items you get a coupon for $6 off." "This costs $10 and these are $5 each."
Now how could I interrupt that to "do school"? I did eventually come in and buy some things from their stores and was impressed by my older daughter's mental math calculations when giving me change. I tried to push it farther when SK told me that a certain item was 5 for $20 and I asked how much for only 4. She wasn't quite ready for that.
Later we went down and had lunch and continued our planned school, but it was a wonderful homeschooling moment to watch the learning in action.