Lesson objective: Identify the tens and ones that make two-digit numbers.

This lesson helps to build procedural skill with composing and decomposing two-digit numbers with/into their component tens and ones. Base ten blocks are used here because it supports understanding the components of two-digit numbers. This work develops students' understanding that two-digit numbers are made up of tens and ones.

Students engage in Mathematical Practice 7 (students continue to explore the structure of place value; they will see the system for grouping numbers into the tens and ones that compose the numbers) as they compose and decompose two-digit numbers with/into their component tens and ones.

**Key vocabulary:**

- ones place
- place value
- tens place

**Special materials needed:**

- base ten blocks
- hundred chart