Unit Length and Description:
20 days
From Grade 1, students have fluency of
addition and subtraction within 10 and extensive experience working with
numbers to 100. Unit 1 of Grade 2 reviews and extends addition and
subtraction strategies that will help to provide each student with practice
to achieve mastery of the new required fluencies (i.e., adding and
subtracting within 20 and within 100) by the end of the year. Students learn
to represent and solve word problems using addition and subtraction: a
practice that will also continue throughout the year.

Standards:
OA
 Operations and Algebraic Thinking

Represent and solve problems
involving addition and subtraction.

2.OA.A.1

Use
addition and subtraction within 100 to solve one and twostep 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.

Add and subtract within 20.

2.OA.B.2

Fluently
add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all
sums of two onedigit numbers.

NBT – Number and Operation in Base Ten

Use
place value understanding and properties of operations to add and subtract.

2.NBT.B.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.B.6

Add up
to four two‐digit numbers using strategies based on place value
and properties of operations.

Standards for
Mathematical Practice

1. Make sense of problems and persevere
in solving them.
2. Reason abstractly and
quantitatively.
3. Construct viable arguments and
critique the reasoning of others.
4. Model with mathematics.
5. Use appropriate tools strategically.
6. Attend
to precision.
7. Look for and make use of structure.
8. Look for and express regularity in
repeated reasoning.

Instructional
Outcomes
·
2.OA.1:
o
I can identify the number of
steps to solve a word problem.
o
I can identify an unknown number
in an equation using addition and subtraction up to 100.
o
I can identify the
strategy/strategies for solving word problems. (Is it addition or
subtraction?)
·
2.OA.2:
o
I can know from memory all sums
and differences of 2 onedigit numbers within 20.
o
I can use mental strategies to
add and subtract fluently within 20.
·
2.NBT.5:
o
I can identify the order in
which to add threedigit numbers. (e.g. adding right to left)
o
I can identify properties of
operations to add. (e.g. associative and commutative properties)
o
I can identify properties of
operations to subtract. (e.g. associative and commutative properties)
·
2.NBT.6
o
I can identify strategies for
adding up to four twodigit numbers based on place value.


Enduring Understandings:
·
I can
think about numbers in different ways.
·
I can
show numbers in all kinds of ways.
·
Knowing
about numbers helps me answer everyday questions, such as, “how many” and
“how much”.
·
There
is more than one way to solve a problem.
·
Addition
and subtraction are opposite operations.
·
I can
compose and decompose a number.
·
Knowing
my basic facts helps me to solve other problems.

Essential Questions:
·
What are different ways we can show or make (represent) a
number?
·
Why do
I use numbers to show “how much” and “how many”?
·
How can
I solve the same problem in more than one way?
·
How are
addition and subtraction opposite operations?
·
How can
I compose and decompose a number?
·
How can
I use the basic facts to solve other problems?
