1ST GRADE NUMBER

OPERATIONS AND ALGEBRAIC THINKING 

Represent and solve problems involving addition and subtraction 

1.OA.A.1 Use addition and subtraction within 20 to solve 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
Sample Activities:
Add to: Result Unknown Word Problems 
Take From: Change Unknown Word Problems
Math Literature Link: Anno's Counting House
Math Literature Link: Two of Everything
Math Literature Link: Ten Flashing Fireflies
Also included in 1st Grade Math Centers:
Math Literature Link: Baby Goes to Market
Math Literature Link: Handa's Surprise
Math Literature Link: One Duck Stuck
Math Literature Link: The Very Hungry Caterpillar
Math Literature Link: Rooster's Off to See the World
Math Literature Link: Mouse Count
Add to: Result Unknown Word Problems
Add To: Start Unknown Word Problems
Take From: Result Unknown Word Problems
Take From: Start Unknown Word Problems
Put Together/Take Apart: Total Unknown Word Problems
Put Together/Take Apart: Both Addends Unknown Word Problems
Put Together/Take Apart: Addend Unknown Word Problems
Compare: Difference Unknown Word Problems
Compare: Bigger Unknown Word Problems
Compare: Smaller Unknown Word Problems
Mixed Addition/Subtraction Word Problems

1.OA.A.2 Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, e.g. by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.
Sample Activities:
Three Addends Word Problems 
Also included in 1st Grade Math Centers:
Three Letter Addends
Three Addends Unknown 
Find 3 Cards

Understand and apply properties of operations and the relationship between addition and subtraction

1.OA.B.3 Apply properties of operations as strategies to add and subtract. Examples: If 8+3=11 is known, then 3+8=11 is also known (Commutative property of addition). To add 2+6+4, the second two numbers can be added to make a ten, so 2+6+4=2+10=12 (Associative property of addition).
Sample Activities:
Turn Around Trains
Turn Around Dominoes
Also included in 1st Grade Math Centers:
Domino Related Facts
Three Addends

1.OA.B.4 Understand subtraction as an unknown-addend problem. For example, subtract 10-8 by finding the number that makes 10 when added to 8.
Sample Activity:
Subtract from Ten
Also included in 1st Grade Math Centers:
Ten Frame Subtraction
Think Addition for Subtraction (v. 1-4)

Add and subtract within 20

1.OA.C.5 Relate counting to addition and subtraction (e.g. by counting on 2 to add 2).
Sample Activities:
Show One More
Show One Less
Also included in 1st Grade Math Centers:
Show One More/One Less

1.OA.C.6  Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g. 8+6=8+2+4=10+4=14); decomposing a number leading to a ten (e.g., 13-4=13-3-1=10-1=9); using the relationship between addition and subtraction (e.g. knowing that 8+4=12, one knows 12-8=4); and creating equivalent but easier or known sums (e.g., adding 6+7 by creating the known equivalent 6+6+1 =12+1=13).
Sample Activities:
Count On One (v. 1)
Count On One (v. 2)
Find Ten
Make Ten 
Doubles Path
Near Doubles Path
Four in a Row Subtraction
Also included in 1st Grade Math Centers:
Count on Two (v. 1-2)
Count On Three (v. 1-2)
Count On Cover Up (within 10)
Doubles Concentration
Doubles Cover Up (v. 1)
Cuisenaire Doubles
Doubles Towers
Doubles Plus One Towers
Doubles Plus Two Towers
Sums of Ten
Make Ten with Cuisenaire Rods
Make Ten on the Ten Frame
Towers of Ten
Make a Ten (v. 1-3)
Make a Ten Cover Up
Make a Ten Path
Math Fact Sort (Set 1 & 2)
Fact Family House
The Difference Game (v. 1-3)
Four in a Row Subtraction
Addition Train
Race to 50
Cuisenaire Triangles
Build a Cuisenaire House
Domino Addition
Part-Part Whole Cards

Work with addition and subtraction equations

1.OA.D.7 Understand the meaning of the equal sign, and determine if equations involving addition and subtraction are true or false. For example, which of the following equations are true and which are false? 6=6, 7=8-1, 5+2=2+5 , 4+1=5+2
Sample Activity:
True or False?
Also included in 1st Grade Math Centers:
Equal Sums

1.OA.D.8 Determine the unknown whole number in an addition or subtraction equation relating to three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8+ ? =11, 5 = □ – 3, 6+6 = □
Sample Activity:
Find the Missing Number

NUMBER AND OPERATIONS IN BASE TEN

Extend the counting sequence

1.NBT.A.1 Count to 120, starting at any number less than 120. In this range, read and write numerals and represent a number of objects with a written numeral.
Sample Activities:
Base Ten Path
Counting Collections (v. 1-2)
Also included in 1st Grade Math Centers:
Ten Frame Path
Number Path
Missing Number Grids (1-50)
Counting Cards (Set 3)
Estimate and Count 

Understand place value
1.NBT.B.2 Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:
a. 10 can be thought of as a bundle of ten ones – called a “ten.”
b. The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
c. The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).
Sample Activities:
Tens and Ones with Snap Cubes
Build a Train 
Also included in 1st Grade Math Centers:
Tens and Ones Game
Make Ten Bundles
Representing Two-Digit Numbers
Base Ten Concentration (2 Digit)
My Double Ten-Frame Riddle

1.NBT.B.3 Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.
Sample Activities:
Comparing Two-Digit Numbers
Greater Than 50
Also included in 1st Grade Math Centers:
Ten Frame Compare
Scoop It
Who Has the Greater Sum? (v. 1)
Who Has the Greater Sum? (v. 2)

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

1.NBT.C.4 Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, 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 and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones, and sometimes it is necessary to compose a ten.
Sample Activities:
Sums of 90  
Lucky Six
Subtract 10 on the Number Line 
Addition Split (2 digit + multiple of 10)
Also included in 1st Grade Math Centers:
Adding a 2-Digit and 1-Digit Number
Add Ten
Adding Tens to a 2-Digit Number  
Add Ten on the Number Line
What Number is ...?
Adding a Multiple of 10 (ver. 1)

1.NBT.C.5 Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.
Sample Activities:
Ten More
Race Around -10 (v.1)
Also included in 1st Grade Math Centers:
Race Around + 10 (v. 1)

1.NBT.C.6 Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), 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 and explain the reasoning used.
Sample Activities:
Subtract Ten
Subtract Multiples of Ten

ADDITIONAL 1ST GRADE NUMBER RESOURCES
Identify, continue and label patterns.  Create patterns using number, shape, or color.
Number Patterns
Also included in 1st Grade Math Centers:
Pattern Cards
Growing Patterns
Make a Pattern