Problem-solving in math: making a plan
CCGPS: MCC2.OA.3 Determine whether a group of objects (up to 20) has an odd or even number of members, e.g., by pairing objects or counting them by 2s; write an equation to express an even number as a sum of two equal addends.
CCGPS: MCC2.OA.2 Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers.
What does it mean to have a plan?
About 1 hour
chart paper (poster for problem solving)
Overview or notes pertaining to lesson:
Students will learn the second step in the problem-solving process: Make a Plan
Review yesterday’s discussion about Step 1 of the problem solving process: Read and Understand. Explain that today we will be working on Step 2: Plan. What does it mean to have a plan? Have students turn and talk and then share a few ideas with the class. When you plan, you decide what is going to be the best thing for you to do. Mathematicians always need to have a plan to get them to an answer. There are many different strategies that we can use to help us. Introduce the strategies one at a time: Draw a picture, find a pattern, guess and check, manipulatives, make a list, table/chart, number sentence, work backwards, make it simpler. You might want to pre-make the list of strategies, or print this one for students to glue in their math journals for a reference. But on your chart paper, I think it is best to pre-make the list and draw examples of each strategy, so students can easily see what manipulatives they can use, what a chart, number sentences, lists, etc look like. Explain that we don’t use all of these strategies at once. We have to think about the problem and what we understand about the problem to decide which strategy would be best for solving the problem.
Use the exemplar problem from yesterday’s lesson: Lynn’s Ladder. Review what we understood about the problem yesterday. Ask students which strategy they think would be best to help us solve this problem. Turn and talk, then share ideas. Probably the best strategy for this question would be “draw a picture”. Write “Plan” under “Read and Understand” and write: I am going to draw a picture of the ladder that Lynn is painting.
We will be practicing some of these strategies today in our groups. Again split students into groups that you have been using. Group 1: pattern activity with base ten blocks from day 7, Group 2: teacher-allow students to practice the “Plan” step with a different exemplar problem (use the same one you used in the last lesson), Group 3: tic tac toe, Group 4: odd/even game. After about 10 minutes, clap for attention, clean up, and rotate. Remember to correct behaviors immediately and praise good behaviors.
Journal Entry: What are your favorite math strategies, or which do you feel most comfortable using?