

Unit 5 Addition and Subtraction Within1000 with Word
Problems to 100 Grade 2 Math 


Description: In Unit
5 students use place value strategies, manipulatives, and math drawings to
extend their conceptual understanding of the addition and subtraction algorithms
to numbers within 1000. They maintain addition and subtraction fluency within
100 through daily application problems to solve one and twostep word
problems of all types. Students use place value reasoning to explain why
their addition and subtraction strategies work. 

Louisiana Student Standards for Mathematics
(LSSM) 





Enduring Understandings: ·
When one quantity is joined or added on to
another quantity, the result is greater than or equal to the initial
quantity. ·
When one
quantity is removed from another quantity, the result is less than or equal
to the initial quantity. ·
Joining, removing, partpartwhole, and
comparing problems can be modeled. ·
Addition and subtraction can be composed
and decomposed to simplify the operation. ·
Mental math strategies may be used to solve
problems involving numbers. ·
Problems can be solved in a variety of ways
such as modeling, number bonds, tape diagrams, counting strategies, or
standard algorithms. ·
Problems
and solutions can use various representations, including concrete objects,
pictures, number sentences, and words. 
Essential Questions: ·
How do
we use addition and subtraction to tell number stories? ·
How does
using ten as a benchmark number help us add and subtract? ·
How can we solve
addition problems with and without composing? ·
How can we solve
subtraction problems with and without decomposing? ·
How can strategies
help us when adding and subtracting? ·
How are
addition and subtraction alike and how are they different? ·
How do
we solve problems in different ways? ·
How can
we explain why addition and subtraction strategies work? ·
How can problem
situations and problemsolving strategies be represented? ·
How are problemsolving
strategies alike and different? 


