In Unit 2, students connect written numerals (0  10) to quantities of objects arranged in a line. Students extend their understanding of counting and quantity by exploring equivalent sets which differ in arrangement or the order counted. This unit relies on students’ understanding of the count sequence and onetoone correspondence and looks ahead to counting other arrangements (array, circular, scattered) and extending the counting sequence.
Key Concepts:
 The last number name said tells the number of objects.
 Any number of objects can be represented with a written numeral.
 The number of objects is the same regardless of their arrangement or the order in which they were counted.
Prior Knowledge Needed:
 Count onetoone up to 10; (Grade K, Unit 1)
 Respond with the last number counted when asked “How many?” without recounting; (Grade K, Unit 1)
 Know number names and count sequence 0  10; (Grade K, Unit 1)
Units on the Horizon:
 Apply counting to rectangular arrays of objects; (Grade K, Unit 3)
 Apply counting to scattered arrangements and circular arrangements; (Grade K, Unit 8)
 Extend the counting sequence to read and write numerals to 120; (Grade 1, Unit 8)
Lessons

Lesson objective: Understand that the last number name said represents all of the objects that have been counted so far. Students bring prior knowledge of rote counting to 10 from K.CC.1. This prior knowledge is extended to cardinality as students learn...

Lesson objective: Count a collection and tell how many. This lesson helps to build fluency with counting. Cubes are used here because they support students in flexibly counting with strategies of their own choosing. This work develops students' understa...

Lesson objective: Count to answer "How many?" and then build a collection to match. This lesson helps to build fluency with counting to tell how many. Cubes are used here because they support students as they model a collection they have counted. This w...

Lesson objective: Undertsand that a written numeral can be used to represent the count of a set of objects. Students bring prior knowledge of rote counting to 10 from K.CC.1. This prior knowledge is extended to written numerals as students connect their...

Lesson objective: Write the numerals 0  10 to represent sets of objects. This lesson helps to build fluency with writing the numerals 0  10. Different groups of objects are used here because they support students growing fluency with counting and quan...

Lesson objective: Identify written numerals to match sets of objects. This lesson helps to build fluency with using the numerals 0  10 to represent sets of objects. Ten frames are used here because they support students in using strategies for identify...

Lesson objective: Connect written numerals with sets of objects. This lesson provides an opportunity for students to apply their knowledge and understanding of written numerals to a reallife situation. Students are asked to organize a set of marbles by...

Lesson objective: Understand that the number of objects is the same regardless of arrangement or the order counted. Students bring prior knowledge of rote counting to 10 from K.CC.1. This prior knowledge is extended to counting sets in different orders ...

Lesson objective: Find sets of objects that are arranged differently, but represent the same number of objects. This lesson helps to build fluency with the idea that multiple representations can be used for the same number of objects. Dot cards are used...

Lesson objective: Solve problems by creating and counting various arrangements of the same number. This lesson provides an opportunity for students to apply their knowledge and understanding of counting to a reallife situation. Students are asked to cr...