Lesson 2

The Mouse-Proof Shelf

Est. Class Sessions: 1–2
X

Mathematical Standards

2.NBT.A
Understand place value. (2.NBT.A.2, 2.NBT.A.4)
2.NBT.B
Use place value understanding and properties of operations to add and subtract. (2.NBT.B.5, 2.NBT.B.7)
2.OA.A
Represent and solve problems involving addition and subtraction. (2.OA.A.1)
2.OA.C
Work with equal groups of objects to gain foundations for multiplication. (2.OA.C.4)

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.
MP7.
Look for and make use of structure.

In the Adventure Book story, “The Mouse-Proof Shelf,” four mice apply what they have learned about mass to balance a tilting lamp. The students find combinations of mass that will balance pairs of mice.

Content in this Lesson

  • Using words and symbols (e.g., <, >, =) to show comparisons of
    quantities [E2].
  • Comparing and ordering quantities [E3].
  • Recognizing that different partitions of a number have the same total
    (e.g., 50 + 4 = 40 + 14) [E4].
  • Applying the properties of addition (e.g., commutative, associative) to write number sentences that represent mass [E5].
  • Solving addition problems and subtraction (e.g., part-whole, join, take away, compare) involving mass [E6].

Daily Practice and Problems E–F

E. Story Solving

F. Centimeters

X

Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Books

 Student Activity Book
Adventure Book

Teacher Resources

 Teacher Guide - digital

Supplies for Student Pairs

30 connecting cubes
two-pan balance

Materials for the Teacher

Display of Jill, Sally, Marty, and Bob Did It (Student Activity Book) Pages 391–392
Unit 8 Assessment Record
30 connecting cubes
two-pan balance

Materials Preparation

Prepare Display of Characters in Adventure Book. Write the names of the characters and the color or patterns of their shirts on a chart or other display. The list will make it easier for students to keep the characters straight as you read the story.

  • Jill: red, striped
  • Sally: green, plain
  • Marty: blue, zigzag
  • Bob: orange, speckled

Assessment in this Lesson

ASSESSMENT EXPECTATION ASSESSED
Compare Numbers
with Feedback Box
Student Activity Book
Pages 393–394
E2.
Use words and symbols (e.g., <, >, =) to show comparisons of quantities.
E3.
Compare and order quantities.
E4.
Recognize that different partitions of a number have the same total
(e.g., 50 + 4 = 40 + 14).
E5.
Apply the properties of addition (e.g., commutative, associative) to write number sentences that represent mass.
E6.
Solve addition and subtraction problems (e.g., part-whole, join, take away) involving mass.

Vocabulary in this Lesson