This SMART Notebook file was designed to be used with classroom Smartboards. The file includes 14 slides that each contain four mathematical items that involve either numbers or geometry. On each slide children need to determine which item doesn't belong with the others, either because it is missing a specific attribute that the other three have or because it has a specific attribute that the other three don't have. You can use multiple slides in one period or spread them out throughout the year. Determining which item doesn't belong provides children with wonderful practice identifying similarities and differences, promotes paying close attention to detail, and offers multiple opportunities to re-visit and review important math concepts. With the eight slides that contain numbers, you and your students can touch on numerous place value skills, including odd and even, rounding, sums, and differences. With the six slides featuring polygons, you and your students can touch on concepts such as the names of geometric shapes, parallelism, and regular and irregular polygons. In addition, extra slides are included as templates, from which you can create even more examples to use in class. On every slide there is always more than one correct answer, and highlighting these various possibilities leads to interesting classroom discussions.
Which One Doesn't Belong?
by Steve Reifman
is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License