CCSS Cluster Unit
SUBJECT:
Math
UNIT:
Adding & Subtracting
GRADE:
3rd
SECTION 1: Desired Results
CLUSTER: 3-2: The student will demonstrate through the mathematical processes
an understanding of the representation of whole numbers and fractional parts; the
addition and subtraction of whole numbers; accurate, efficient, and generalizable
methods of multiplying whole numbers; and the relationships among multiplication,
division, and related basic facts.
INDICATORS: 3.NBT.2 Fluently add and subtract within 1000 using strategies and algorithms based on place value,
properties of operations and/or the relationship between addition and subtraction.
IMPORTANT CONCEPTS:
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POSSIBLE MISCONCEPTIONS:
Number sense
Operation (larger, smaller)
Regroup/trade
Place value
Greater /less
Equations/number sentence
Fluency
Inverse relationship between adding and
subtracting
Algorithm
Strategies
Symbols
Estimation
Plus, sum, equal, same as, minus, subtract
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addition/subtraction inverse
lining up numbers (place value)-vertical and
horizontal problems
symbols
put smaller number on top
regroup (too much, not regrouping, not
knowing when)
regrouping with 0
operation of subtraction (top to bottom)
FOCUS QUESTIONS:
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Can students identify the relationship between addition and subtraction?
Can students transfer between vertical and horizontal alignment?
Can students take a word problem and decide operation/information needed to solve the problem?
Do students know when to regroup/trade versus when not to? (with and without zeros)?
Students will know: (nouns)
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Place value
Addends, sum
Minuend, subtrahend, difference
Regroup/trade
Algorithm
Students will be able to: (verbs)
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Understand place value
Regroup/trade
Use symbols correctly
Create a number sentence
Choose, apply, and explain their strategy
Self-evaluation (check for reasonable answers)
CCSS Cluster Unit
SUBJECT:
Math
UNIT:
Adding & Subtracting
GRADE:
3rd
SECTION 2: Assessment Evidence
PERFORMANCE TASK(S):
The answer to a subtraction problem is 578. Create a
number sentence and story problem where the
answer is 578. Show your work.
SAMPLE TEST ITEMS:
Tommy and Sally have a seashell collection. Tommy
has collected 476 seashells, and Sally has collected
498. How many seashells have Tommy and Sally
collected in all?
Answer: __________ seashells
Explain how you found your answer or show your
work.
SECTION 3: Instructional Tasks
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Base ten blocks/other manipulatives
Create strategy posters with alternative methods/anchor charts of different algorithms (see addition
and subtraction algorithms)
Use real-life or contextual problems
Estimation strategies (front-end estimation)
Math journals/letters to help students practice showing their work and explaining their answer
Doubling to 1,000 (game)
Difference add (game)
Section 4: Resources
Addition and subtraction algorithms reference sheet
http://nlvm.usu.edu/ virtual base-ten blocks that will join and break apart to help with regrouping (can use
pre-made problems or enter your own numbers)
Interactive games
http://www.sheppardsoftware.com/mathgames/fruitshoot/fruitshoot_addition.htm addition and
subtraction; multi-digit numbers; can choose level