Kaylee Bisby | 2nd Grade Math on Instagram: "Here’s how 👇 But first, comment “open number line” and I’ll send you my blog post sharing my full lesson plan. Before teaching a new strategy, we always want think about what mental math skills do students need in order to be successful. For open number line, students need to know how to subtract 10 and 1 from a 2-digit number. I’ll pre-teach these skills as math warm-ups leading up to our Subtraction on an Open Number Line lesson. Then when we get t