Estimate At A Best Buy Near You.

     Recently, we turned our classroom into Best Buy. Pictures of electronics such as IPODs, PS3s, and Nintendo DSs decorated our room. My students wrote an estimation story, detailing their "shopping experience." I gave each kid $710 (just pretend :) to spend on two items of their choice. They browsed the "store," wrote the actual price of each item, and then estimated each cost by rounding it to the nearest hundred. They used a strategy we like to call the "Sky to Floor" number line. The goal is to do estimation mentally, however, the number line helps them to "see" the closest hundred in their brain. After finding the estimated costs, they added them to see if they could afford both with just $710. For example, if a PS3 costs about $300 and an IPOD costs around $200, then the total estimated cost would be about $500. You could buy both.

     Through this experience, I want my students to realize that estimating actual amounts like exact prices makes them easier to remember and easier to add. I estimate all of the time when I go shopping, and I hope they do too, the next time you get the itch to spend a few dollars.