• Unit Overview

  • Letter Home
  • Unit Preparation
  • Mathematics in this Unit
  • Assessment in this Unit
  • Key Assessment Opportunities Chart
• Daily Practice and Problems
• Home Practice

• Lesson 1

  • Part 1: Developing Strategies for Problems with Sums to Twenty
  • Part 2: Sorting Sums
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

• Lesson 2

  • Part 1: Creating a Visual Representation of Doubling Numbers
  • Part 2: Doubles and Counting Numbers
  • Summarizing the Lesson
  • Homework and Practice
  • Literature Connection
  • Answer Keys

• Lesson 3

  • Part 1: Doubling and Halving as Inverse Operations
  • Part 2: Using Connecting Cubes to Double and Halve
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

• Lesson 4

  • Part 1: Doubles and Near Doubles
  • Part 2: Play Doubles, Doubles +1, Doubles −1
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

• Lesson 5

  • Developing the Lesson
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

• Lesson 6

  • Part 1: True or False Number Sentences
  • Part 2: Finding Missing Numbers
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

• Lesson 7

  • Part 1: Build Addition Strategies Menu for Larger Numbers
  • Part 2: Practice with Addition Strategies for Larger Numbers
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

• Lesson 8

  • Developing the Lesson
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

• Lesson 9

  • Developing the Lesson
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

• Lesson 10

  • Part 1: Build a Subtraction Strategies Menu
  • Part 2: Practice Subtraction Strategies
  • Summarizing the Lesson
  • Homework and Practice
  • Answer Keys

Lesson 9

Subtraction Strategies

Est. Class Sessions: 2

Daily Practice and Problems

X

Teacher Notes

X

1. 6 days; 8 +  6 = 14
2. 5 days; 9 +  5 = 14
3. 31 days; 8 + 14 + 9 = 31

Ask students in which months could this data could have been collected. Data was collected for 31 days so the data could have been collected during January, March, May, July, August, October, or December.

DD. Weather Problems

Use the graph to solve each problem.

1. How many more partly cloudy () days were there than sunny () days?
   
   Number Sentence ______________________________
2. How many more partly cloudy () days were there than cloudy () days?
   
   Number Sentence ______________________________
3. How many days were in this month? ______________________________