3rd Grade mathematicians are building conceptual frameworks for division using a variety of modes of learning and participation. Our warm-ups each day in math are designed to expand a math process skill and to revisit, retrieve and rehearse prior content skills. This Wednesday, students warmed up by solving a series of three-digit mental subtraction problems, then shared their strategies aloud in a Number Talk. They said things like, “I added 5 to 475 to get a better number like 480. Then it would be 20 to get to 500 so I added 5 again…”
I added 5 to 475 to get a better number like 480. Then it would be 20 to get to 500 so I added 5 again…
Teachers asked probing questions like, “Did anyone think about this one differently?” And together, in just a few minutes, we saw that many strategies worked to solve each problem, and some strategies were more or less efficient in each case. New terms like “divisor” were introduced in the mini-lesson, then students worked with a “turn & talk” neighbor to decide which of two given division expressions matched a story context. Turned out, both expressions did!
Back at their tables, students worked on practice problems with a partner to determine, for each of a few story contexts, which visual diagram and which expression matched. For example, Jada has six blocks and uses them to build two equal stacks. How many blocks is in each stack? What diagram below shows this? And which expression of 6÷2 or 6÷3 matches? Or, Han has six blocks and stacks them with two blocks in each stack. How many stacks are there?
After checking their work, students showed what they knew on the lesson’s “cool down” then broke out into choice-based math games, all of which are designed, with varying complexity, to reinforce mental strategies for addition and subtraction. In the Math Challenge small group pull-outs, some students seeking more challenge were tasked with solving a problem about an unusual baker, using fraction and division concepts to solve a complex problem about cakes divided into various numbers of slices and finding the price per slice.