Numbers and Operations in Base Ten (2a): Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases: A. 10 can be thought of as a bundle of ten ones — called a “ten.”

Quarter 1 (Continued throughout the year)

Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:

a. 10 can be thought of as a bundle of ten ones —
called a “ten.”

This includes representing 100 with a "flat" base ten block (in quarters 2 - 4).
** Continue in quarters 2, 3, and 4 through routines and classroom discussion.

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Understanding place value leads to number sense and efficient strategies for computation.

Essential Questions

How does a digit's position affect its value?

Vocabulary (online dictionary, HCPSS Vocabulary Cards)

Hundred Chart Spin

Place Value, Digit

About the Math

The concept of ten is a foundational skill in primary mathematics. Students must be able to compose ten in order to add and subtract as well as understand the value of a number. Understanding the composition of a two-digit number is equally important. Students need ample practice so that understanding is intuitive rather than rote or memorized.

There are many different models that can be used to develop the concept. Models for grouping incude: Beans and small paper cups (for groups of 10), Linking cubes, and/or Digi-blocks.

Pregrouped models include: Base-ten blocks, five and ten-frames, and place value mats.
Virtual base ten blocks , Chip Abacus, and hundred charts are good electronic resources.
Beans and sticks for place value.

Bundled straws on a pv mat.

Rich Tasks for Multiple Means of Expression, Engagement, and Representation (UDL)

1. Have students use base ten blocks, ten frames, digi blocks, and other concrete materials to represent whole numbers. Be sure to stress the connection between the model and place value.

2. Demonstrate how you can set up values in different ways. I can show 3 tens and 6 ones, or 2 tens and 16 ones and still have the same amount of objects. This leads into trading values for addition and subtraction, and exchanging coins while keeping the same value.

3. Ask the students to show 89 in two different ways. I can see that 89 is made of 5 tens, 3 tens, and 9 ones or that is simply 1 one away from 90, or 7 tens and 19 ones, or it is 50 and 39 more. Being able to decompose numbers and building the concept that each representation is indeed the same value aides in efficient and affective mental computation.

Journal Prompt:

How many different "teen" numbers can you show on your double ten frame? Draw a picture and write a number sentence to show how many more than ten each number is.

Print Resources:

Math by All Means Place Value 1-2
Brain-Compatible Activities for Mathematics K-1
Mental Math in the Primary Grades
Nimble with Numbers 1-2
Developing Number Concepts Place Value
Developing Number Concepts Place Value, Multiplication, and Division(34-35)
Developing Mathematics with Unifix Cubes
Math Intervention: Building Number Power K-2

Web Resources

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Games and Centers
Student Resources
Video Segments
Printable Game
Base Ten Concentration (2 Digit)

Two Digit Numbers with Base 10 Blocks

Printable Centers
My Double Ten-Frame Riddle-
Tens and Ones Game

Make 10 Bundles

Teens on the Ten Frame

Online Games
Place Value Practice

Shark Pool Place Value

Full Lesson

Where's My Place?

Lesson SeedsUnderstanding and Using Tens and Ones

Mystery Number (Game/Lesson Seed)
Student Resource Sheet
Teens on the Ten Frame Book Template
Place Value Instructional Ideas
Beg. Math Adventures of Lollipop Dragon:Place Value-
Hundred Chart Spin


Contact John SanGiovanni at

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Howard County Public Schools Office of Elementary Mathematics Curricular Projects has licensed this product under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.