This lesson focuses on three standards: 3.OA.C.7, 3.OA.A.3, and 3.OA.D.8. During the warm-up part of the lesson, students practice strategies for multiplication families to build fluency. The second part of the lesson focuses on writing and solving a single step multiplication word problem. In the last part of the lesson, students work collaboratively to solve a two-step word problem involving multiplication and subtraction. Core Actions 2 and 3 are exhibited in this lesson.
Two-step Word Problems (Dolan)Download
In this part of the lesson, students are finishing up working on daily math problems. They began by working independently on the problems at their seats. When they finish, they find a partner and explain how they solved the problems to each other. They check to see if they agree or disagree on the answers. The teacher is simultaneously walking around and checking for student understanding.
In this part of the lesson, students are sharing the word problems they wrote to match the number sentence 7 x 3 = 21. As the teacher is circulating and checking understanding, she notices that some students have written addition story problems instead of multiplication problems. She adjusts the lesson by calling the class back to whole group and clarifies the difference between an addition problem and a multiplication problem. She calls on the students to help her change an addition story problem into a multiplication problem.
In this part of the lesson, the teacher is reviewing with students how they know when to add, subtract, multiply or divide in the context of word problems. She calls on students to share how they know which operation to use in each word problem. The teacher asks, "What made you think it was multiplication?" "What made you think it was a subtraction problem?" "What made you think this was a dividing story problem?" and "What do they want to know?"
Here, the teacher leads the students through an example problem that requires multiple steps in order to solve. The teacher asks the students how many "jobs" (operations) they have to do to solve this problem. She asks, "Do you think that's important information to solve this problem?" She asks them to think about what they need to do first to solve it. The students perform the first operation. The teacher asks, "Are we done? Did we answer the question the problem asked? What do we have to do now?" The students perform the second step using a different operation.
In this part of the lesson, the students are working in small groups to solve a multi-step word problem. The students can be observed talking through their strategy and responding to one another's thinking. Students are counting by 9s, four times. Then they are taking 36 and subtracting 12. In another group a student is suggesting using base-ten to show the subtraction (drawing longs and dots to represent 36 and crossing off one ten and two dots). A student in the same group suggests doing it another way to see if they got the right answer.
In this last part of the lesson, the teacher has called students back to whole group to have small groups share how they solved the problem. She reminds students that there might be multiple ways to arrive at the same answer and the important part of sharing is learning new and different strategies from other students. Four different groups come up to the board to share their solution methods. The teacher facilitates by asking questions to get students to explain each step.