The bands are made from 1-1/2” wide elastic sewed together to form a loop. (Although my teenager looked at them and asked, “Why don’t you just use Chinese jump ropes?” Hmmm. . . that might have been simpler!!) Students form groups of 4-5. As I call out various shapes, groups use the elastic (geoband) to form the shape. As I walk around to each group, they must DESCRIBE attributes, or PROVE why their shape is what it is. For example, a square would have 4 right angles and 4 equal sides; a trapezoid is a parallelogram with 1 set of parallel sides. They start to understand and use the mathematical vocabulary (& love using their bodies!)
Another way to use vocabulary to demonstrate understanding is writing regularly in math journals. After lots of oral discussion and modeling (love the document camera for this!!), students are encouraged to explain their strategies.
We celebrate “bloopers,” or mistakes that help lead us to the answer. I encourage students to NOT erase, but SHOW their thinking process. As a weekly homework assignment, my students use Math at Home, a monthly problem solving booklet. They choose one problem per week to solve. They must explain their thinking strategy and steps in pictures, words, and numbers. Although initially difficult, students become proficient in using mathematical vocabulary in their writing! Check out my 4th Grade Math at Home booklets here!here.
I also want to know what my students know about concepts before I formally teach. Placemat Consensus is a very effective pre-assessment. In groups, students draw a large (empty) circle in the center of a large piece of butcher paper and then mark a section off so they each have a “placemat” in front of them. Set the timer for 10 minutes and students independently write and draw everything they know about a concept. Next, students share their placemat to the rest of their group members. If everyone in the group agrees with their ideas (comes to consensus), a recorder adds it to the middle of the circle. Lastly, each group presents their findings to the class. This is a terrific way to assess their content vocabulary and understandings.