We have a winner! The Instructify staff has voted Mister Teacher‘s “Punch it Up” rounding technique as the best mnemonic device we received. It’s a great way to teach young students the concept of rounding, and is also really catchy. But we’ll let Mister Teacher himself explain:
When I teach my third graders how to estimate, I use a process that one of my buddies taught me long ago called, “Punch It Up.”
Let’s say that you want to round the number 86 to the nearest 10. The preliminary step is to identify place values, but the meat of estimation comes in knowing whether to round a number up or down. So the kids know that they are analyzing the number 6 in 86. They hold up 6 fingers. With 6 fingers, they are able to make a fist, and with that fist they can, “Punch It Up” to 90. If the number had been 84, and they had been holding 4 fingers up, they would see that they are NOT able to make a fist to punch it up, so they have to just let go of it and let it drop down to 80.
To punch it up, you have to have at least 5 fingers in order to make a fist. The kids really take hold of this concept and get excited about rounding.
For his efforts, Mister Teacher wins a Philips GoGear MP3 player, which he can then load with other catchy educational phrases. Or, you know, music.
If you’re an elementary teacher, consider using the “Punch it Up” method in your own math lessons. Just be sure to thank Mister Teacher for sharing this great trick. -BILL FERRIS
Photo credit: Jaume d’Urgell on flickr