Grade Two Chapter 6 - 3-Digit Addition and Subtraction
Overview & Support
Standards:
Use place value understanding and properties of operations to add and subtract.
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.7.1
Use estimation strategies to make reasonable estimates in problem
solving. CA
2.NBT.9
Explain why addition and subtraction strategies work, using place
value and the properties of operations.
Suggested Routines:
 Number Talks
 hundred charts
 Choose 3 Ways
 Think-Pair-Share
 Think-Negotiate-Talk
 open number lines
 Fluency Builder
 secret code cards
*Have students practice their “Make a 10” strategy daily using cards with 1, 2, 3,
4, 5, 5 6, 7, 8, 9 for each student. Use it as a warm up where each student matches
the pairs to “Make a 10”.
*Use Math Mountain Cards (fact family triangle) cards to practice addition and
subtraction for fluency.
Manipulatives:
base ten blocks
whiteboards
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grab-and-go
Vocabulary:
digit
word form
total sum
compare
order value
regroup ones
addition
place value
expanded form
period
number line
reasonable estimate
regroup tens
difference
standard form
partial sum table
population
open number line
round
addend
inequality symbols (equal
sign, greater than sign,
less than sign)
Strategies for Chapter:
 Using the standard algorithm is not the focus of these lessons. Students
should know how to regroup 10 ones as 1 ten, and may be exposed to the
algorithm, but are not expected to master it. It is recommended that
teachers focus on strategies that build understanding of place value such as
quick pictures, compensation, decomposition, and partial sums.
 expanded form using number and word forms
Color Coding:
Green (G) – The lesson accurately reflects the Framework standard(s).
Yellow (Y) - This lesson includes notes to refer to while planning the lesson.
Red (R) - This lesson does not accurately reflect the Framework standard(s). Skip
the lesson.
Essential Question:
 What are some strategies for adding and subtracting 3-digit numbers?
Lesson-by-Lesson Overview:
Lesson #,
Standard
Show
What You
Know
6.1
G
2.NBT.7
Title
Materials
Show What
You Know
Draw to
Represent 3Digit Addition
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Vocab
Notes
Number
cards 1050,
30 two
sided
counters
# 6, #7 on pg. 284 reference the
Framework
p. 8-Put together/take apart
6.2
Y
2.NBT.7
6.3
Y
2.NBT.7
Break Apart 3Digit Addends
3-Digit
Addition:
Regroup Ones
Base-ten
blocks
addition
bar
partial sum
total sum
addend
expanded
form
reasonable
estimate
regroup
ones (in
addition)
#8 on pg. 288 reference California
Framework on pg. 18
Look at Common Errors on pg. 286
Reference California Framework Figure
2-3 on pg. 18
Do pages 289 and 292. Do not do pgs.
290-291 as if it focuses on standard
algorithm which is not a second grade
standard. Use base-ten blocks and
quick pictures to represent regrouping
standard algorithm method
Look at Common Errors on pg. 290
6.4
Y
2.NBT.7
3-Digit
Addition:
Regroup Tens
regroup
tens (in
addition)
Reference California Framework Figure
2-3 on pg. 18 for additional ways to
draw composed units
Reference California Framework Figure
2-3 on pg. 18
Remember - don’t focus on standard
algorithm!
6.5
Y
2.NBT.7
Addition:
Regroup Ones
and Tens
estimate
Look at Common Errors on pg. 294
Pages 293 and 296 can be done. Pages
294-295 focus on algorithm.
Preview and part of this lesson is outside
of standard.
Mid Chapter Checkpoint
Use alternate methods for problems 2-4
Using Formative Feedback – Correct the Mid-Chapter Checkpoint and use the data for:
#2-4 allow for quick pictures, break apart, or base-ten strategies
●
Math centers or math games focused on standards of need
●
Small group instruction focused on a single standard/common error
●
Whole group instruction focused on a single standard/common error
●
My Favorite No – Rewrite student work with an error and work as a class to identify
positives in the work and areas that need to be revised
●
Select 1 – 3 problems to resolve in their groups and discuss whole class (do not just
review the checkpoint item by item – this is not very engaging. We want new learning to
occur on this day that helps students over misconceptions.
6.6
Estimation in
New lesson
G
3-Digit
2.NBT.7.1 Addition
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6.7
G
2.NBT.7
6.8
Y
2.NBT.7
6.9
Y
2.NBT.7
2.NBT.9
6.10
Y
2.NBT.7
6.11
Y
2.NBT.7
6.12
G
2.NBT.7.1
Reteach
Options
Problem
Solving: 3-Digit
Subtraction
3-Digit
Subtraction:
Regroup Tens
Reference California Framework Table
2-3 pgs. 8-10 for different types of
addition and subtraction problems
Remember - don’t focus on standard
algorithm!
Use variety of methods
# 10 on pg. 312 is a two-step problem
Remember - don’t focus on standard
algorithm!
3-Digit
Subtraction:
Regroup
Hundreds
Subtraction:
Regroup
Hundreds and
Tens
Regrouping
with Zeros
Use variety of methods
Remember - don’t focus on standard
algorithm!
Use variety of methods
bar models
Estimation in
3-Digit
Subtraction
#17 on pg. 320 is adding on
Remember - don’t focus on standard
algorithm!
Quick picture; Base-ten model
Remember - don’t focus on standard
algorithm!
Look at Common Error on pg. 326
Reteach Day – Look over your Chapter 6 Assessment to determine
standards/areas of need/common errors. Reteach standards from this unit to help
meet students’ need. Some ideas for reteach activities are listed below:
Have students practice their “Make a 10” strategy daily using cards with 1, 2, 3, 4,
5, 5 6, 7, 8, 9 for each student. Use it as a warm up where each student matches
the pairs to “Make a 10”.
*Use Math Mountain Cards (fact family triangle) cards to practice addition and
subtraction for fluency.
● Math centers or math games focused on unit standards
● Small group instruction focused on a single standard
● Whole group instruction focused on a single standard
● My Favorite No – Rewrite student work with an error and work as a class to
identify positives in the work and areas that need to be revised
● Select 1 – 3 problems to resolve in their groups and discuss whole class (do
not just review the test item by item – this is not very engaging. We want new
learning to occur on this day that helps students over misconceptions.
● Complete the “Performance Task” from Go Math! In the Assessment Book in
small groups. Share strategies and discuss whole class.
Use the Reteach activities based on standards that need intervention.
Chapter Assessment:
Chapter 6 Review/Test available in Student Edition
Alternate summative assessment available online in Assessment Guide
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