Workshop: Addition and Subtraction

Review student work and progress from previous lessons to guide instructional decisions about the following Expectations:

E1.

Show that different partitions of the same number are equal using base-ten pieces, number lines, and number sentences (e.g., 200 + 30 + 7 = 200 + 20 + 17).

E2.

Represent and solve addition problems using base-ten pieces and number lines.

E3.

Represent and solve subtraction problems using base-ten pieces and number lines.

E4.

Solve addition and subtraction problems using mental math strategies (e.g., composing and decomposing numbers, counting up, and counting back).

E6.

Add multidigit numbers using paper-and-pencil methods (expanded form, all-partials, and compact).

E7.

Subtract multidigit numbers using paper-and-pencil methods (expanded form and compact).

E9.

Choose appropriately from among mental math, estimation, and paper-and-pencil methods to add and subtract whole numbers.

In Lessons 1–6 of this unit, students focused on whole number concepts, place value, and on the addition and subtraction operations. They explored representing numbers and partitions of numbers using base-ten pieces and number lines. These representations were extended to solve addition and subtraction problems. This work lays the conceptual foundation for solving problems using paper-and-pencil methods (all-partials, expanded form, and compact).

In Part 2 of the lesson, students will identify their level of confidence with a particular concept and choose problems from a Workshop Menu. Use your own evaluation of students' progress to help guide their choices.

Plan to organize the class into partners or small groups based on problems they select. These groups may change as the workshop progresses.

Plan to have students play the Digits Game in small groups in Part 1 of this lesson. Students played this game in Grade 3 and should have revisited the game as a class in the Daily Practice and Problems in Unit 3 and in DPP items M and AA in this unit. If students are not familiar with this game, you may need to play a few more rounds as a class before students are ready to play in small groups.