Unpacking the Standards
Grade 2
Standard: 2.OA.1 Cluster (m)
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.
Essential Skills/Concepts / Teaching Notes/Strategies / Resources· Add to 100
· Subtract within 100
· Draw symbols to represent unknowns
· Explain thinking using words, symbols, and writing
· Understand the situation in the word problem
· Understand different types of add/subtract problems (See Framework p. 7)
· Understand there are different strategies to solve / - Model drawings
- Manipulatives
- Scaffold problems from one-step, to two-step, etc.
- Use trade books with word problems to collaboratively solve (i.e. After reading The Napping House, solve this word problem: When all the sleepers were piled up, how many feet were in the bed? Use pictures, numbers or words to show your thinking.)
- Anchor charts for sharing symbols
- Board math
- Daily word problem
- Students use document camera to demonstrate and justify their thinking
- Students write word problems for their classmates to solve / * One Hunter by Pat Hutchins (at K-5 Math Resources below)
* The Napping House by Audrey Wood (at K-5 Math Resources below)
* P. Bear’s New Years Party by Paul Owen Lewis(at K-5 Math Resources below)
* http://www.k-5mathteachingresources.com/2nd-grade-number-activities.html
* math journals
* PUSD problem solving poster
* www.cde.gov (Appendix F – more defined methods for solving single-digit addition/subtraction problems)
Standard: 2.OA.2 Cluster (m)
Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers.
Essential Skills/Concepts / Teaching Notes/Strategies / Resources· Adding and subtracting within 10
· Counting on
· Convert to an easier problem
· Determine a strategy to use
· Fluency of computing
· Make 10 / - Games in centers
- Domino or dice games (choose two and find sum)
- Interactive games from NCTM
- Living chart of strategies (counting on, making tens, decomposing a number leading to ten, fact families, doubles, doubles plus 1)
- Math journals for strategies
- Number talks
- Board math
- Magic Square game (try to get each row to equal a given number)
- Number webs
- Make posters for student-developed mental strategies
- Flash cards
- Computer games
- Dots/dot patterns / * Two of Everything by Lily Toy Hong (activity at K-5 Resources site below)
*Ten frames/double ten frames
*Magic Square game at
http://illuminations.nctm.org/ActivityDetail
.aspx?ID=75
* http://www.k-5mathteachingresources.com/2nd-grade-number-activities.html
Standard: 2.OA.3 Cluster (s)
Determine whether a group of objects (up to 20) has an odd or even number of members, e.g., by pairing objects or counting them by 2’s; write an equation to express an even number as a sum of two equal addends.
Essential Skills/Concepts / Teaching Notes/Strategies / Resources· Count by 2’s
· Write addition equations for doubles
· Count 1-20
· Group objects into pairs
· Understand concept of even vs. odd
· Explain why a number is even or odd / - Songs for odd and even
-Using manipulatives (grab a handful and record how many pairs you have and how many extras)
- Modeling with concrete objects for grouping
- Odd and Even read alouds
- Have groups of students pair up in different pairings to determine even or odd when lining up
- Board math
- Using objects, find the numbers that will have some objects remaining and no objects remaining after separating the collections into two equal groups / * Manipulatives for grouping
* Doubles song/chant
* “Even Song” sung to Bingo (There was a farmer had a cow and Even was her name-o, 0,2,4,6,8)
* Even Stephen Odd Todd by Kathryn Cristaldi
* If You Were an Odd Number (Math Fun) By Marcie Aboff
* My Even Day and One Odd Day by Doris Fisher
Standard: 2.OA.4 Cluster (s)
Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.
Essential Skills/Concepts / Teaching Notes/Strategies / Resources· Understand repeated addition
· Write equations with multiple addends
· Recognize equal parts
· Counting by multiples/skip count
· Make equal groups/rows / - Walk the number line multiple times
- Use clearboard grids with counters
- Make arrays with a set number of counters (record all possibilities)
- Have students sit in arrays on the rug and use equation to calculate
-Board math / * Grid paper
* Clear board grids
* Pattern blocks for building arrays
* Number line on floor
* Making arrays activities at http://www.k-5mathteachingresources.com/2nd-grade-number-activities.html