Grade 2: Unit Summaries

Unit 1: Coins, Number Strings, and Story Problems (26 Sessions)

Addition, Subtraction, and the Number System 1

This unit focuses on adding and subtracting single-digit numbers, focusing particularly on adding numbers in any order; shifting from counting by 1s to counting by groups, particularly groups of tens and ones, which lays the foundation for students’ work with place value and the base-10 number system; and developing and refining strategies for solving a variety of addition and subtraction problems. As the first unit in Grade 2, it also introduces the mathematical tools, processes, and ways of working that will be the foundation of math class. As part of this work, students are introduced to several year-long classroom routines that offer regular practice with composing and decomposing numbers, developing visual images of quantities, addition and subtraction facts, telling time, and counting, collecting, and analyzing data.

• Investigation 1: Introducing Math Tools and Classroom Routines (6 Sessions)
• Investigation 2: Does Order Matter? (8 Sessions)
• Investigation 3: Comparing Quantities and Counting by Groups (7 Sessions)
• Investigation 4: Solving Story Problems (5 Sessions)
• Unit 2: Attributes of Shapes and Parts of a Whole (19 Sessions)

Geometry and Fractions

The focus of this unit is on observing and describing defining attributes of 2-D and 3-D shapes (e.g., number and shape of faces, number and length of sides, and number of angles and vertices), and using those attributes as they sort, construct, draw, and compare shapes. This unit also develops ideas about equal parts of a whole, focusing specifically on partitioning and describing halves, fourths, and thirds of one whole and recognizing that the same equal part of a whole (e.g. one half of a square) can be different shapes.

• Investigation 1: Attributes of 2-D and 3-D Shapes (5 Sessions)
• Investigation 2: Quadrilaterals, Rectangles, and Squares (6 Sessions)
• Investigation 3: Halves, Quarters, and Thirds (8 Sessions)

• Unit 3: How Many Stickers? How Many Cents? (24 Sessions)

Addition, Subtraction, and the Number System 2

This unit focuses on the place value of 2-digit numbers, and operating on those numbers within 100. Students come to see 100 as ten 10s and multiples of 100 as being made up of some number of hundreds. They solve a variety of types of story problems (e.g. put together/take apart with one or both addends unknown, add to and take from with result unknown, problems with an unknown change or an unknown start). They play games that involve combining amounts to get to 100 or \$1. Work on fluency with addition and subtraction within 100 continues, with a focus on using known facts and knowledge of the operation. Students also identify, read, and write numbers to 500, and mentally add and subtract 10 to numbers in that range.

• Investigation 1: Sticker Station (8 Sessions)
• Investigation 2: Adding and Subtracting Within 100 (9 Sessions)
• Investigation 3: Problems with an Unknown Change or an Unknown Start (7 Sessions)
• Unit 4: Pockets, Teeth, and Guess My Rule (12 Sessions)

Modeling with Data

This unit focuses on sorting and classifying categorical data; ordering numerical data; and collecting and representing categorical and numerical data using a variety of representations: student-generated representations, picture graphs, bar graphs, Venn diagrams, cube towers, and line plots. Students describe the data, and discuss what the data tell them about the group surveyed. In doing so students develop the ability to model with data, aspects of their world.

• Investigation 1: Working with Categorical Data (6 Sessions)
• Investigation 2: Working with Numerical Data (6 Sessions)
• Unit 5: How Many Tens? How Many Hundreds? (20 Sessions)

Addition, Subtraction, and the Number System 3

This unit focuses on the place value of 3-digit numbers and operating on numbers within 100. Students come to see 100 as 10 tens and multiples of 100 as being made up of some number of hundreds. They solve a variety of types of story problems (e.g., put together/take apart with one or both addends unknown, add to and take from with result unknown, problems with an unknown change or an unknown start). They play games that involve combining amounts to get to 100 or \$1. Work on fluency with addition and subtraction within 100 continues, with a focus on using known facts and knowledge of the operations. Fluency with addition within 100 is a benchmark in this unit. Students also identify, read, and write numbers to 1,000 and add and subtract 10 and 100 to numbers in that range.

• Investigation 1: Combinations of 100 (6 Sessions)
• Investigation 2: Adding within 100 and Counting to 1,000 (6 Sessions)
• Investigation 3: Fluency within 100 (8 Sessions)
• Unit 6: How Far Can You Jump? (12 Sessions)

Linear Measurement

This unit focuses on developing strategies for accurately measuring length with nonstandard and standard units (e.g., craft sticks, cubes, inches, feet, yards, centimeters, and meters) and tools (e.g., inch-brick measuring tools, rulers, yardsticks, and meter sticks) and for considering the relationship between different units and tools (e.g., the larger the unit, the smaller the count will be). Students represent measurement data on a line plot and also solve story problems that involve adding, subtracting and comparing lengths.

• Investigation 1: The Land of Inch (6 Sessions)
• Investigation 2: Two Measurement Systems (6 Sessions)
• Unit 7: Partners, Teams, and Other Groups (10 Sessions)

Foundations of Multiplication

The focus of this unit is on working with equal groups as the foundation of multiplication by investigating even and odd numbers and by representing equal groups with arrays and tables.

• Investigation 1: Is It Even or Odd? (4 Sessions)
• Investigation 2: Exploring Equal Groups (6 Sessions)
• Unit 8: Enough for the Class? Enough for the Grade? (20 Sessions)

Addition, Subtraction, and the Number System 4

This unit focuses on developing and achieving fluency with subtraction within 100, and on achieving fluency with addition and subtraction facts within 20, which students have been working on throughout the year. Students are also introduced to a new type of story problem—comparison problems with a smaller unknown. They end the year thinking about how the strategies they know and use for adding and subtracting 2-digit numbers translate to adding and subtracting 3-digit numbers, represented with place-value notation. Students also demonstrate fluency with time, work that has been happening all year long, ending the year telling time to the nearest five minutes, using A.M. and P.M.

• Investigation 1: Subtraction: Fluency within 100 (11 Sessions)
• Investigation 2: Models for Adding and Subtracting Larger Numbers (9 Sessions)
•