Unit Plan 7 (Grade 1 Math): Tens & Ones—Place Value Basics

Focus: Bundle groups of 10; understand that two-digit numbers show tens and ones; use compose/decompose moves to keep track.

Grade Level: 1

Subject Area: Mathematics (Number & Operations in Base Ten)

Total Unit Duration: 5 sessions (one week), 45–60 minutes per session

I. Introduction

Students build the idea that 10 ones = 1 ten by physically bundling and using place-value mats. They learn to represent, say, read, and write two-digit numbers as tens and ones, and to compose/decompose numbers by exchanging 10 ones ↔ 1 ten.

Essential Questions

• How does making a bundle of 10 help me keep track when I count?
• How do tens and ones show the value of a two-digit number?
• When should I compose (make a ten) or decompose (break a ten) to represent numbers?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Build and explain 10 ones = 1 ten using objects and drawings.
2. Represent any two-digit number as tens and ones on a place-value mat.
3. Compose and decompose numbers by exchanging 10 ones for 1 ten (and back).
4. Read and write two-digit numerals and describe them in tens/ones language.

Standards Alignment — CCSS Grade 1 (threaded across the unit)

• 1.NBT.2a–c: Understand that 10 can be thought of as a bundle (a “ten”); the numbers 11–19 are a ten and some ones; the numbers 10, 20, 30, … are tens with 0 ones.
• Mathematical Practices: MP.7 (Look for and make use of structure) emphasized; MP.1–MP.2, MP.6, MP.8 threaded.

Success Criteria — Student Language

• I can show a number with tens and ones and tell what each part means.
• I can make a ten from 10 ones and break a ten into 10 ones.
• I can read and write two-digit numerals and explain them with tens/ones words.