The students in this lesson utilized a variety of tools to solve, illustrate, and write an equation for addition and subtraction word problems with 20. The word problems involved situations of adding to, taking from, putting together, and taking apart, with unknowns in various positions. Some of the problems called for addition of three whole numbers whose sum was less than or equal to 20. The students worked with partners to solve grade-level problems.
Addition & Subtraction Word Problems (Scott)Download
The teacher intentionally relates new concepts to students' prior skills and knowledge. The teacher has students discuss in partners and small groups the strategies and tools utilized for solving word problems in previous lessons.
The teacher establishes a classroom culture in which students explain their thinking well enough for other students to understand. The student elaborates with a second sentence to explain her thinking and connect it to her first sentence.
The teacher makes the mathematics of the lesson explicit by using explanations, representations, and examples. Students are asked to provide an illustration, equation, and a written explanation of how they solved the number story.
The teacher uses variation in students' ways of thinking, representations, and solution methods to strengthen the students' understanding.
The teacher encourages reasoning and problem solving by posing challenging problems that offer opportunities for productive struggle. The student persevered in solving the problem even after encountering difficulty initially.