Grade 1 Number Concepts

1.NBT.B.2

About the Math

Full Standard

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

10 can be thought of as a bundle of ten ones — called a “ten.”
The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).

Learning Targets (I can)

Represent 10 as ten ones.
Represent numbers 11 to 19 as a ten and some ones.
Represent two-digit numbers using physical tools, drawings, and number names (2 tens is 20, 2 tens and 7 ones is 27).
Explain the value of each digit in a two-digit number (place value).
Locate a two-digit number on a hundred chart and number line.
Represent a two-digit number in more than one way (35 can be 3 tens and 5 ones or it can also be 2 tens and 15 ones)

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.

Represent 10 as ten ones.

Ten ones become a ten just as ten tens become a hundred and ten hundreds become a thousand. Students need ample practice bundling. Though this likely occurred in kindergarten, practice is likely needed in grade 1 as well. Using varied tools is important. Consider ten frames, beans on sticks, cm cubes in dixie cups, digi-blocks, and of course base ten blocks - knowing that they cannot be grouped but are instead exchanged. This can be problematic early in first grade.

Represent numbers 11 to 19 as a ten and some ones.

Students were exposed to this idea in kindergarten. This is the natural extension of the previous learning target. Once this is understood deeply students should transfer this idea to numbers 21-29, 31-39, and so on. Students should see that all of these are related.

Represent multiple sets of ten using physical tools, drawings, and number names (2 tens is 20).

Models support this learning target. Here, students should connect their representations to number charts and other tools. Number lines are appropriate later in grade 1. Students should work with pre-grouped models such as base ten blocks and ungrouped models such as digi-blocks or manipulative ten frames. Proportionate models (including those named) are also recommended. Disproportionate models can be used for extending student thinking. Virtual base ten blocks , Chip Abacus, and hundred charts are good electronic resources.

Explain the value of each digit in a two-digit number (place value).

Digits represent value. 93 represents 9 tens and 3 ones whereas 39 represents 3 tens and 9 ones. There is a considerable difference between the two. Moreover, these two are located at different places on a hundred chart, on number lines, and with different base ten models. Students need to understand that 37 can be named as 37 ones or grouped by tens to be 3 tens and 7 singles. So the way we say a number such as "thirty-seven" needs to be connected with the grouping by tens concept. There are several ways to use the base-ten language for a number such as 37. Thirty-seven can be 3 tens and 7; 3 tens and 7 ones; 3 groups of ten and 7 leftovers; 3 tens and 7 singles. All of these can be used to describe the meaning of "thirty-seven." If appropriate, this learning target can be extended to representing a number in multiple ways. For example, 37 can be shown as 3 tens and 7 ones or 2 tens and 17 ones, or simply 37 ones.

Locate a two-digit number on a hundred chart and number line.

As students develop an understanding of two-digit numbers through base ten models, we should begin to connect the understanding to hundred charts and number lines. Students should first work with ticked number lines and move to open number lines if understanding is evident. In grade 1, it is recommended to rely on hundred charts and ticked number lines.

Essential vocabulary for this standard includes place value, digit, value, hundred chart, number line, and group.

Progression of Standard within Grade 1

This progression informs how to develop the standard within the grade level. This progression is provided by HCPSS Elementary Mathematics.

Quarter 1

Quarter 2

Quarter 3

Quarter 4

Represent 10 as ten ones.
Represent numbers 11 to 19 as a ten and some ones.
Represent multiple sets of ten using physical tools, drawings, and number names (2 tens is 20).
Explain the value of each digit in a two-digit number (place value).
Locate a two-digit number on a hundred chart and number line.

Represent 10 as ten ones.
Represent numbers 11 to 19 as a ten and some ones.
Represent multiple sets of ten using physical tools, drawings, and number names (2 tens is 20).
Explain the value of each digit in a two-digit number (place value).
Locate a two-digit number on a hundred chart and number line.

* This includes representing 100 with a "flat" base ten block.

**Revisit this standard through routines, independent practice, discussions, and other activities.

**Revisit this standard through routines, independent practice, discussions, and other activities.

Progression of this Standard Across Grades

This progression is informed by the Achieve the Core Coherence Map. Information is not the complete standard.

Kindergarten	Grade 2
Compose and decompose numbers from 11 to 19 into ten ones and some ones (K.NBT.1)	Understanding of place value and bundling. ( 2.NBT.1 )

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Preferred Resources

Preferred Tasks

These links are HCPSS created instructional tasks. These tasks are provided in Google slides. When selected, a copy of the file is added to your drive for classroom use.

Module 5 • Bundle Tens and Ones

10 as a bundle of ten ones, represent numbers to 19:

Quick Images
Creating Quick Images
Teen Number Review

10 as a bundle of ten ones, represent numbers to 99:

Module 6 • Word Problems (Change Unknown), Place Value, and Basic Facts (Make Ten/Subtract from Ten)

10 as a bundle of ten ones, represent numbers to 99 by decomposing in different ways:

Lesson Seeds (Prompts for Rigor)

Rigorous mathematics instruction balances the teaching and learning of conceptual understanding, procedural understanding, and the application of mathematics standards. Below are prompts for applying rigor in your classroom. They may support small group instruction or whole group collaborative investigations. They are intended to serve as a starting point for planning . See the Increasing Rigor page for more information.

How many different ways can you represent 82 using tens and ones?
Does 4 tens and 8 ones have the same value as 3 tens and 18 ones? Explain your thinking.
Do 2 tens and 6 ones have the same value as 2 ones and 6 tens? Use models and/or hundreds chart to help explain your answer.
A two-digit number has more tens than ones. What could the number be? What is another possibility?
The sum of the digits of a two-digit number is12. Use a hundred chart, what could the number be? What is another possibility?
How are the numbers 30 and 35 alike? How are they different?
Kendra made a two-digit number with a 6 in the ones place. What possible numbers could she have made?

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Additional Resources

Additional Tasks and Lesson Seeds

These links provide instructional ideas connected to this standard.

Build It with Task Cards (HCPSS)
Roll & Build (Illustrative Math)
Understanding and Using Tens and Ones (Mathwire)
Where's My Place (HCPSS Lesson)
Hundred Board Logic (Mathwire)
Guess My Number (Mathwire)
Tallies, Ten Frames and Baseball Games (NCTM Illuminations Lesson)
Let's Count to 20 (NCTM Illuminations Lesson)
Banker (Utah Core Academy Lesson)
Bull's Eye (Utah Core Academy Lesson)
Numbers 11-19 (Utah Core Academy Lesson)
Bundles of Flowers (Utah Core Academy Lesson)
3 Little Pigs and Ones (Utah Core Academy Lesson)
Number Construction (Utah Core Academy Lesson)
City Scape (Utah Core Academy Lesson)
Place Value Gallery (Utah Core Academy Lesson)
Halloween Candy (Utah Core Academy Lesson)
Additional Ideas

Print Resources

These publications have been provided for each school. They are typically stored in team closets or the media center. Check with your team leader if you cannot find them.

Book Title	Grade	Pages
Teaching Student-Centered Mathematics	K-3	Ten and Some More, Activity 2.26, Page 55 Groups of Ten, Activity 5.2, Page 130
Nimble with Numbers	1-2	(104, 110-112)
Brain Compatible Activities for Mathematics	K-1	(23-25)
Math Intervention: Building Number Power	K-2	(59-63, 107-110, 79-83, 46-49)
Developing Mathematics with Unifix Cubes:		(70-71)
Math by All Means Place Value	1-2	(56-71)
Roads to Reasoning	1	Mystery Number (38-39)
Math In Practice Teaching First-Grade Math	1	Module 8

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Independent Work

Centers

These print resources can be used during independent or center time. These resources could also be used as lesson seeds.

Create a Snake (HCPSS-adapted resource)
What's my Number (HCPSS-adapted resource)
Making Groups of Ten (HCPSS-adapted resource)
Memory Base 10 (HCPSS-adapted resource)
Snap! for Teen Numbers (HCPSS-adapted resource)
Spin and Create Numbers (HCPSS-adapted resource)
Ten Frame Teen Numbers (HCPSS-adapted resource)
Spinning Ten and Some More (HCPSS-adapted resource)
Ten and Some More Match (HCPSS-adapted resource)
Teen Numbers (print resource)
Hundred Chart Magic (print resource)

online Practice

These links provide online resources to engage students during independent or center time.

Independent Practice

These resource sheets can be used for independent practice or homework. They are intended to reinforce procedures and concepts. They should not be used as a source of direct instruction or whole-group practice.

HOmEWoRK

These resource sheets can be used for independent practice or homework. They are intended to reinforce procedures and concepts. They should not be used as a source of direct instruction or whole-group practice.

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Assessment

Learning Targets

Represent 10 as ten ones.
Represent numbers 11 to 19 as a ten and some ones.
Represent two-digit numbers using physical tools, drawings, and number names (2 tens is 20, 2 tens and 7 ones is 27).
Explain the value of each digit in a two-digit number (place value).
Locate a two-digit number on a hundred chart and number line.

Learning targets identify what students should be able to do. The resources below can be used to measure student understanding of the standard. The rubric can be applied to any tasks and observations for assessment and/or grading.

Rubric for Tasks (pdf)

Assessment Tasks

These tasks align with the learning targets for the standard. They can be combined with other tasks for extended assessment opportunities. Teachers/students are not expected to complete all these tasks.

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