Unit Overview
Content Area: Math
Unit Title: Addition of 3-Digit Numbers with & w/out Regrouping
Unit: 6
Target Course/Grade Level:
2
Timeline: 3 weeks
Unit Summary: Students will apply addition regrouping strategies for three digit numerals.
Primary interdisciplinary connections: Language Arts
NJ Standard 9.1: 21st – Century Life & Career Skills
Standard 9.1: All students will demonstrate the creative, critical thinking, collaboration, and problemsolving skills needed to function successfully as both global citizens and workers in diverse ethnic and
organizational cultures.
Strand: A. Critical Thinking and Problem Solving
C. Collaboration, Teamwork and Leadership
Content Statement:
9.1.4.A.5: The ability to recognize a problem and apply critical thinking and problem-solving
skills to solve the problem is a lifelong skill that develops over time.
9.1.4.C.1: Practice collaborative skills in groups, and explain how these skills assist in
completing tasks in different settings such as home, play or school.
21st century themes and skills: Critical Thinking and Problem Solving, Collaboration, Teamwork and
Leadership
Mathematical Practices:
2.MP.1. Make sense of problems and persevere in solving them.
2.MP.2. Reason abstractly and quantitatively.
2.MP.3. Construct viable arguments and critique the reasoning of others.
2.MP.4. Model with mathematics
2.MP.6. Attend to precision.
2.MP.7. Look for and make use of structure.
2.MP.8. Look for and express regularity in repeated reasoning.
Learning Targets
Domain: Numbers and Operations in Base Ten 2.NBT
Measurement and Data 2.MD
Operations and Algebraic Thinking 2.OA
Cluster:
Understand place value.
Use place value understanding and properties of operations to add and subtract.
Work with time and money.
Represent and interpret data.
Standard #
Standards
2.NBT.2
Count within 1000; skip-count by 5s, 10s, and 100s.
2.NBT.4
Compare two three-digit numbers based on meanings of the hundreds, tens, and ones
digits, using >, =, and < symbols to record the results of comparisons.
2.NBT.5
Fluently add and subtract within 100 using strategies based on place value, properties of
operations, and/or the relationship between addition and subtraction.
2.NBT.7
Add and subtract within 1000, using concrete models or drawings and strategies based on
place value, properties of operations, and/or the relationship between addition and
subtraction; relate the strategy to a written method. Understand that in adding or
subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and
tens, ones and ones; and sometimes it is necessary to compose or decompose tens or
hundreds.
2.NBT.8
Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from
a given number 100–900.
2.NBT.9
Explain why addition and subtraction strategies work, using place value and the properties
of operations.
2.MD.10
Solve simple put-together, take-apart, and compare problems using information presented
in a bar graph.
2.OA.1
Use addition and subtraction within 100 to solve one- and two-step word problems
involving situations of adding to, taking from, putting together, taking apart, and
comparing, with unknowns in all positions, e.g., by using drawings and equations with a
symbol for the unknown number to represent the problem
CPI#
Cumulative Progress Indicator (CPI)
9.1.4.A.5
Apply critical thinking and problem-solving skills in classroom and family settings.
9.1.4.C.1
Practice collaborative skills in groups, and explain how these skills assist in completing
tasks in different settings (at home, in school, and during play).
Unit Essential Questions
 How can I use what I know about number
relationships to add and subtract?

Why is recognizing what strategy to use
for a specific purpose, helpful?
Unit Enduring Understandings
 A math sentence can be written to solve for
unknown information in either addition by
utilizing the inverted operation.
 Numbers follow a pattern that repeat, even
when place value changes.
 Symbols (<, >, =) can be used to compare
the value of numbers.
 Different strategies (mental, paper, drawing)
can be used to add numbers fluently.
 Different strategies (mental, paper, drawing,
concrete models) can be applied to add
within 1000.
 Place value affects the other place values
when adding. (regrouping, trading,
composing/decomposing)
 When adding two or three digit numbers,
knowing the value of that digit, in a given
position, determines the next step one must
take to solve an equation.



Multiples of 10 and 100 can be used as
landmark numbers in computation.
Words or drawings can be used to explain
addition strategies.
Picture & Bar graphs charts and tables can
be used to solve comparative and addition
problems.
Unit Learning Targets
Students will ...
 Add 3 digit numbers mentally without regrouping. (2.NBT.8)
 Use manipulatives to show regrouping of hundreds, tens and ones. (2.NBT.7)
 Compute addition problems of 3 digit numbers (w/&w/o regrouping) (2.NBT.5)
 Add two three-digit numbers and record in vertical format.(2.NBT.9)
 Solve problems involving addition using data from a table.(2.MD.10)
 Find missing addends of a three digit problem (2.NBT.8) (2.OA.1)
 Apply knowledge of number patterns to extend existing patterns with numbers within 1000
(2NBT2)
Evidence of Learning
Summative Assessment
 Illustrate/explain adding three-digit numbers with/without regrouping.
 Accurately compute two & three, three-digit numbers with/without regrouping for addition.
 Give a table with various three-digit numbers and solve addition with/without regrouping.
 Choose from a list of strategies/tools one could use to solve a given three-digit math addition
equation to determine which is the best way to attain the correct answer.
 Give an equation using 2 three-digit numbers. Solve the problem giving an estimate and exact
sum.
 Accurately extend three-digit number patterns from any given number up to 1,000.
Equipment needed: place value blocks, decks of cards, dice, number spinners
Teacher Instructional Resources:
Everyday Math
Math Their Way
Scott Foresman Mathematics Program: Chapter 11
Formative Assessments
Observe students as they ….



work with manipulatives
complete work sheets/workbooks
play games, complete activities
Integration of Technology:
SMARTBoard to play online games and utilize on line resources.
ELMO to use for demonstration purposes.
Utilize resources from Scott Foresman by using Login in:
https://www.pearsonsuccessnet.com/snpapp/login/login.jsp
Technology Resources:
Click the links below to access additional resources used to design this unit:
http://www.mrnussbaum.com/draggable/index3.html This is a worksheet to create problems, solve them
and computer tells Student if it is correct.
http://www.mathplayground.com/wpdatabase/wpindex.html Word problems using three digit numerals.
Student is given feedback by computer for answer’s accuracy.
Opportunities for Differentiation:
Decelerate: Continue using place value blocks and/or beans for longer time so the concept of regrouping
is clearly understood. Use the Scott Foresman online tools to give another visual aide for learning the
concept.
Accelerate: Give students four, five and/or six digit numbers to add.
http://www.mathsonline.co.uk/nonmembers/gamesroom/bugs/bugrace3.html Student is expected to add
two numbers quickly before bug lands at bottom.
http://www.netrover.com/~jjrose/random/container.htm Student puts in an answer to given problem and
computer announces if correct or incorrect.
Teacher Notes: It is best to approach three digit addition after students are proficient in two digit addition
and only after revisiting the use of place value cubes to concretely show how regrouping works.