Lesson 6

Making Connections

Estimated Class Sessions: 2–3
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Mathematical Standards

2.NBT.A
Understand place value. (2.NBT.A.1, 2.NBT.A.2)
2.NBT.B
Use place value understanding and properties of operations to add and subtract. (2.NBT.B.6, 2.NBT.B.7, 2.NBT.B.8, 2.NBT.B.9)
2.MD.B
Relate addition and subtraction to length. (2.MD.B.6)
2.OA.A
Represent and solve problems involving addition and subtraction. (2.OA.A.1)

Standards for Mathematical Practice

MP2.
Reason quantitatively.
MP3.
Construct viable arguments and critique the reasoning of others.
MP5.
Use appropriate tools strategically.
MP6.
Attend to precision.

Students make connections between a variety of mental math and
paper-and-pencil strategies as they solve two-digit and three-digit addition problems. They practice using the expanded-form and all-partials methods, and are introduced to the compact method.

Content in this Lesson

  • Using and applying place value concepts to make connections among representation of numbers [E1].
  • Representing addition problems using base-ten pieces, number lines, and number sentences [E2].
  • Adding two-digit and three-digit numbers using mental math strategies (e.g., composing and decomposing numbers and counting on) using the 200 Chart, base-ten pieces, and number lines [E3].
  • Adding two-digit and three-digit numbers using paper-and-pencil methods (e.g., expanded form, all-partials, and compact) [E4].
  • Estimating sums using mental math strategies (e.g., rounding using benchmarks, using friendly numbers, composing and decomposing numbers, counting on) [E6].
  • Choosing good tools and efficient strategies for solving a problem [MPE2].
  • Checking for reasonableness [MPE3].
  • Communicating problem strategies to others [MPE5].
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Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Books

 Student Activity Book

Teacher Resources

 Teacher Guide - digital

Supplies for Students

base-ten pieces (21 bits, 20 skinnies, 3–5 flats)

Materials for the Teacher

Display of Addition Strategies Menu (Student Activity Book) Page 351
Unit 7 Assessment Record
Math Facts Class Record
Display set of base-ten pieces
Addition Strategies Chart from Lesson 2

Assessment in this Lesson

ASSESSMENT EXPECTATION ASSESSED MATH PRACTICES EXPECTATION ASSESSED
Add Larger Numbers
with Feedback Box
Student Activity Book
Pages 353–355
E1.
Use and apply place value concepts to make connections among representations of numbers to the thousands using base-ten pieces, number lines, expanded form, and standard form.
E3.
Add two-digit and three-digit numbers using mental math strategies (e.g., composing and decomposing numbers, counting on) using the 200 Chart, base-ten pieces, and number lines.
E4.
Add two-digit and three-digit numbers using
paper-and-pencil methods (e.g., expanded form, all-partials, compact).
E6.
Estimate sums using mental math strategies (e.g., rounding using benchmarks, using friendly numbers, composing and decomposing numbers, counting on).
MPE2.
Find a strategy. I choose good tools and an efficient strategy for solving the problem.
MPE5.
Show my work. I show or tell how I arrived at my answer so someone else can understand my thinking.
DPP Item S
Fact Families Practice:
Group E
Teacher Guide - digital
E7.
Demonstrate fluency with the addition facts in Group E (5 + 7, 8 + 4, 8 + 5, 9 + 3, 9 + 4, 9 + 5, 10 + 1, 10 + 2,
10 + 3).
E8.
Determine the unknown number in an addition or subtraction sentence relating three whole numbers for the facts in Group E.