1st GRADE NUMBER ACTIVITIES: OPERATIONS AND ALGEBRAIC THINKING
Represent and solve problems involving addition and subtraction
1.OA1 Use addition and subtraction within 20 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.
Addition Word Problems
Subtraction Word Problems
Bunk Bed Problem
Double Decker Bus Problem
Making Apple Ten Packs
Read Aloud Task Cards:
One Duck Stuck
The Very Hungry Caterpillar
Rooster's Off to See the World
Two of Everything
1.OA2 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.
Word Problems with 3 Addends
Find 3 Cards
Three Letter Addends
Understand and apply properties of operations and the relationship between addition and subtraction
1.OA3 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) 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).
Turn Around Trains
Turn Around Dominoes
Domino Fact Families
Domino Addition Recording Sheet
1.OA4 Understand subtraction as an unknown-addend problem. For example, subtract 10-8 by finding the number that makes 10 when added to 8.
Ten Frame Subtraction
Add and subtract within 20
1.OA5 Relate counting to addition and subtraction (e.g. by counting on 2 to add 2).
Show One More
Show One Less
One More on the 10 Frame
One More/One Less Scoop
1.OA6 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).
Work with addition and subtraction equations
1.OA7 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
True or False?
1.OA8 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 = ?
Find the Missing Number