Workshop: Addition Strategies

Est. Class Sessions: 2–3

Summarizing the Lesson

Display the problem 293 + 45. Ask students to estimate the sum by rounding using benchmarks, using friendly numbers, composing and decomposing numbers, counting on, thinking about the 200 Chart, or using any other strategy.

Next, ask students to choose a strategy and solve the problem. Remind them to think about all the strategies they practiced during the Workshop. Encourage them to refer to the Addition Strategies Menu from the Student Activity Book Reference section or their version from Lesson 6.

After they have solved the problem, ask them to compare the sum to their estimate to check for reasonableness. If their answer does not make sense, tell them to check their calculations and think about solving the problem using a different method.

When students are confident with their answers, arrange them in small groups to share their solution strategies. After students have shared within their groups, ask them to think about the different methods.

Ask:

Did someone in your group use a mental math strategy?
Did someone use a paper-and-pencil method?
Which strategy did you like the best for this problem?
Did one method seem more efficient than another?
Was one method easier to understand than another?
Is this the strategy that you choose most often? Which strategy do you choose most often? Why?
What do you think about the paper-and-pencil methods? Are they efficient? Easy to use?

Display the Math Practices page from the Student Activity Book. For the next assignment, students will need to focus on finding a strategy [MPE2]; checking for reasonableness [MPE3]; checking calculations [MPE4]; and showing work [MPE5].

Ask:

You will be solving addition problems on the Addition Strategies Quiz. What kinds of tools can you use [MPE2]? (base-ten pieces, 200 Chart, number lines)
Where can you find a list of possible strategies to use? (Addition Strategies Menu)
How can you check for reasonableness and make sure your calculations are correct [MPE3, 4]? (We can estimate first and then compare the estimate to our answer. If the answer doesn´t make sense, we can check our calculations and solve it another way.)

Assign the Addition Strategies Quiz in the Student Activity Book for students to compete individually. Remind students to clearly show or tell their work so that others can understand their thinking.

Use the Addition Strategies Quiz with the Feedback Box in the Student Activity Book to assess students' abilities to use and apply place value concepts [E1]; add two-digit and three-digit numbers using mental math strategies [E3] and paper-and-pencil methods [E4]; estimate sums using mental math strategies [E6]; find a strategy [MPE2]; check for reasonableness [MPE3]; check calculations [MPE4]; and show work [MPE5].

ADVENTURE BOOK: