Lesson 8

Add and Subtract Decimals with Paper and Pencil

Est. Class Sessions: 2–3
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Mathematical Standards

5.NBT.A
Understand the place value system. (5.NBT.A.3)
5.NBT.B
Perform operations with multi-digit whole numbers and with decimals to hundredths. (5.NBT.B.7)

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.
MP6.
Attend to precision.
MP7.
Look for and make use of structure.

Students learn to add and subtract decimals with paper and pencil and create their own strategies menus. Students have the opportunity to practice using estimation and all of their addition and subtraction strategies as they play the Add or Subtract to 1 Game.

Content in this Lesson

  • Adding and subtracting decimals to the hundredths using models and strategies, including paper and pencil [E7].
  • Estimating decimal sums and differences [E9].
  • Representing numbers to the hundredths using circle pieces, grid models, base-ten pieces, number lines, symbols, and words [E1].
  • Making connections among representations of decimal numbers to the hundredths [E2].
  • Comparing decimals to the thousandths using place value understanding [E3].
  • Finding an addition or subtraction strategy [MPE2].
  • Estimating to check for reasonableness [MPE3].
  • Knowing the problem [MPE1].
  • Using labels to show what numbers mean [MPE6].
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Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Books

 Student Guide  
Student Activity Book      

Teacher Resources

 Teacher Guide - digital

Supplies for Students

  • fraction circle pieces
  • base-ten pieces
  • Hundredths Circle Wheel from Lesson 2

Materials for the Teacher

Materials Preparation

Prepare Sets of Digit Cards for Display and Targeted Practice. Each student will need a deck of 30 cards containing 3 sets of Digit Cards 0–9 for the Add or Subtract to 1 Game. If necessary, make 3 copies of the Digit Cards 0–9 Master per student and cut out the cards or have students cut out the cards. Make 6 additional copies so that you can have a deck of cards for display and some for targeted practice. Collect and save the decks of cards for games in the Workshop in Lesson 9.

Assessment in this Lesson

Assessment Expectation Assessed Math Practices Expectation Assessed

Add and Subtract Decimals Quiz
with Feedback Box
Teacher Guide - digital
E1.
Represent numbers to the thousandths using fractions, decimals, words, area models, base-ten pieces, number lines, and expanded form.
E3.
Compare and order decimals to the thousandths using place value understanding and benchmarks.
E7.
Add and subtract decimals to the thousandths using models and strategies.
E9.
Estimate sums, differences, products, and quotients involving decimals and fractions.
MPE2.
Find a strategy. I choose good tools and an efficient strategy for solving the problem.