Lesson 7

Make Connections with Subtraction

Est. Class Sessions: 2
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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

MP1.
Make sense of problems and persevere in
solving them.
MP2.
Reason quantitatively.
MP3.
Construct viable arguments and critique the reasoning of others.
MP4.
Model with mathematics.
MP5.
Use appropriate tools strategically.

Students make connections between a variety of mental math and
paper-and-pencil strategies as they solve multidigit subtraction problems. They solve problems using invented strategies, base-ten pieces, expanded form, and the compact method.

Content in this Lesson

  • Using and applying place value concepts to make connections among representations of multidigit numbers using base-ten pieces, number lines, expanded form, and standard form [E1].
  • Representing subtraction problems using base-ten pieces and number
    lines [E2].
  • Subtracting multidigit numbers using mental math strategies (e.g., composing and decomposing numbers, counting up) with number lines, a 200 Chart, and base-ten pieces [E3].
  • Subtracting multidigit numbers using paper-and-pencil methods
    (e.g., expanded form, compact) [E4].
  • Estimating differences using mental math strategies (e.g., rounding using benchmarks, using friendly numbers, composing and decomposing numbers, counting on) [E5].
  • Choosing good tools and efficient problem-solving strategies [MPE2].
  • Checking for reasonableness [MPE3].
  • Solving problems more than one way to check subtraction [MPE4].
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Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Book

 Student Activity Book

Teacher Resources

 Teacher Guide - digital

Supplies for Students

base-ten pieces (21 bits, 20 skinnies, 5 flats)
desk number line (0–100)

Materials for the Teacher

Display of Fix It (Student Activity Book) Pages 471–472
Display of Subtraction Strategies Menu (Student Activity Book) Page 473
Unit 9 Assessment Record
Math Facts Class Record
Subtraction Strategies Chart from Lesson 2
Display set of base-ten pieces (21 bits, 20 skinnies, 5 flats)

Assessment in this Lesson

Assessment Expectation Assessed
Use Subtraction Strategies
with Feedback Box
Student Activity Book
Pages 475–477
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.
Subtract multidigit numbers using mental math strategies (e.g., composing and decomposing numbers, counting up) with number lines, a 200 Chart, and base-ten pieces.
E4.
Subtract multidigit numbers using paper-and-pencil methods (e.g., expanded form, compact).
E5.
Estimate differences using mental math strategies (e.g., rounding using benchmarks, using friendly numbers, composing and decomposing numbers, counting on).
DPP Item W
Subtraction Facts Quiz: Group A
Teacher Guide - digital
E6.
Demonstrate fluency with the subtraction facts related to the addition facts in Group A (1 − 0, 1 − 1, 2 − 0, 2 − 1, 2 − 2, 3 − 1, 3 − 2, 4 − 1, 4 − 2, 4 − 3,
5 − 2, 5 − 3, 6 − 2, 6 − 4).