Lesson 9

Snack Shop Addition and Subtraction

Est. Class Sessions: 1–2
X

Mathematical Standards

2.NBT.A
Understand place value. (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.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.
MP5.
Use appropriate tools strategically.
MP6.
Attend to precision.

Students solve addition and subtraction problems based on the Shooting Star Snack Shop Children’s Menu that was introduced in Unit 7. Students calculate total snack shop bills and determine the amount of change or the amount of additional money needed.

Content in this Lesson

  • Solving problems about money.
  • Adding and subtracting multidigit numbers using mental math strategies [E3].
  • Adding and subtracting multidigit numbers using paper-and-pencil methods (e.g., expanded form, compact) [E4].
  • Estimating sums and differences using mental math strategies (e.g., rounding using benchmarks, using friendly numbers, composing and decomposing numbers, counting on) [E5].
  • Knowing what information is important in solving a problem [MPE1].
  • Choosing good tools and efficient strategies for solving addition and subtraction problems [MPE2].
  • Using estimation to determine the reasonableness of answers [MPE3].
  • Showing work to explain solution strategies [MPE5].
  • Using labels (e.g., ¢ and $) to show what numbers mean [MPE6].

Daily Practice and Problems EE–FF

EE. Jelly Beans

FF. Reading Minutes

X

Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Book

 Student Activity Book

Teacher Resources

 Teacher Guide - digital

Supplies for Students

set of base-ten pieces (21 bits, 20 skinnies, and 3–5 flats)
desk number line (0–100)
calculator

Materials for the Teacher

Display of Subtraction Strategies Menu (Student Activity Book) Reference
Display of Shooting Star Snack Shop Children's Menu (Student Activity Book) Page 495
Display of Snack Shop Sample Master (Teacher Guide)
Display of Addition Strategies Menu (Student Activity Book) Reference
Unit 9 Assessment Record
Unit 9 Individual Assessment Record
Subtraction Strategies Chart from Lesson 2
display calculator, optional

Assessment in this Lesson

Assessment Expectation Assessed MATH PRACTICES EXPECTATION ASSESSED
Snack Shop Bills
Check-In: Question 6
with Feedback Box
Student Activity Book
Pages 500–501
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).
MPE1.
Know the problem. I read the problem carefully. I know the questions to answer and what information is important.
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 asnwer so someone else can understand my thinking.
MPE6.
Use labels. I use labels to show what numbers mean.

Vocabulary in this Lesson