Garage saling with kids can be very profitable if played right. “Please Daddy, can I get the scooter??? I’ll pay for it with my own money.” Hmm, How much is it? “$12” Hmm.
“I can pay for it with the money I will get from 4-H tomorrow!! Please Daddy?”
Wait for it…
Garage sale proprietor: “He can have it for $5. I just want to get it out of here.”
What percent off was the scooter? Take the change in price divided by the original price.
Change in price: $12-$5=$7.
Percent off: 7/12=.58=58% (Allow the child to use a calculator.)
Sibling: No, I think you would take 5/12.
Parent: Was it more than half off or less?
Sibling: More.
Parent: 5/12 is less than half, 42%. $5 was 42% of the original price paid, but it was 58% *off* of the original price.
It’s amazing how motivating children’s own money can be for learning math!
In this vignette, it was important to allow calculator use so as to focus on finding percent off, versus focusing on long division. The discussion took about five minutes, and longer would have stolen joy from the moment. A follow-up session later could involve checking the work with long division if practice in this area were needed.