3rd Grade Estimating Sums and Differences teaches students to use rounding before adding or subtracting so that they can estimate an answer close to the actual answer in order to check their work. A rounding poem is used to help students remember the steps. There are 22 effective teaching research strategies used in this lesson. In addition, a 20 question digital Easel Assessment is included in order to check students' understanding of the lesson. It is self-checking for students and auto-gr