Lesson 2

The Coat of Many Bits

Est. Class Sessions: 3
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Mathematical Standards

3.NBT.A
Use place value understanding and properties of operations to perform multi-digit arithmetic. (3.NBT.A.1, 3.NBT.A.2)

Standards for Mathematical Practice

MP1.
Make sense of problems and persevere in solving them.
MP2.
Reason quantitatively.
MP4.
Model with mathematics.
MP5.
Use appropriate tools strategically.
MP8.
Look for and express regularity in repeated reasoning.

Students trace an outline of their coats or jackets onto a large sheet of paper and measure the area inside the outline. The data collected through these measurements tend to be “big” (i.e., four-digit) numbers, that are then used in problem situations. After working with these large numbers, students examine place value in the base-ten number system.

Content in this Lesson

  • Showing that different partitions of the same number are equal using base-ten pieces [E1].
  • Representing and solving addition problems using base-ten pieces [E2].
  • Adding multidigit numbers using paper-and-pencil methods (e.g., expanded form) [E4].
  • Measuring area of irregular shapes in square centimeters.
  • Estimating sums using mental math strategies using convenient numbers [E5].
  • Comparing and ordering multidigit numbers.
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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 Student Groups

student's coat (a jacket, sweater, or sweatshirt may be substituted for the coat)
large sheet of paper at least 2 yards by 1 yard
crayons
index card
scissors
tape
set of base-ten pieces: 2 packs, 14 flats, 30 skinnies, and 50 bits

Materials for the Teacher

Display of Centimeter Grid Paper Master (Teacher Guide)
Unit 6 Assessment Record
chart paper

Materials Preparation

Cut Paper or Make Outlines of a Coat. Cut a large sheet of paper at least 2 yards by 1 yard for each student group or make an outline of a coat for each group. See Before the Lesson for a discussion of each method.

Prepare Two Class Tables. Make a table on chart paper as shown in Figure 2 for student groups to record the number of flats, skinnies, and bits needed to cover their coats. See Question 3 in the Student Guide. Students will help create the second class table as shown in Figure 3. To prepare, have a large piece of chart paper where the class can record their answers to Question 6 in the Student Guide.

Figure 2: Class table showing the area as the number of bits, skinnies, and flats

Figure 3: Class table showing the area using the Fewest Pieces Rule

Assessment in this Lesson

Assessment Expectation Assessed

Standard and Expanded Form
Student Activity Book
Pages 175–176
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.