First Grade Operations and Algebraic Thinking

Introduction to addition and subtraction equations, properties of operations and word problems.  Just click on the blue links to display or print pdfs.
Standards

Practice Pages
Represent and solve problems involving addition and subtraction - Cluster 1

Standard 1.OA.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 objects, drawings, and equations with a symbol for the unknown number to represent the problem.
Add Objects

Answers 1.OA.1.a


Subtract Words

Answers 1.OA.1.b

Standard 1.OA.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.
Count Objects

Answers 1.OA.2.a


Mixed Equations

Answers 1.OA.2.b

Understand and apply properties of operations and the relationship between addition and subtraction - Cluster 2


Standard 1.OA.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 + 5 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 - 2 + 10 - 12.  (Associative property of addition.)
Commutative Counting

Answers 1.OA.3.a


Associative Property

Answers 1.OA.3.b

Standard 1.OA.4:  Understand subtraction as an unknown-addend problem. For example, subtract 10 -  8 by finding the number that makes 10 when added to 8.
Take Away Objects

Answers 1.OA.4.a


Subtraction and Addition

Answers 1.OA.4.b

Add and subtract within 20 - Cluster 3


Standard 1.OA.5:  Relate counting to addition and subtraction (e.g., by counting on 2 to add 2)
Add-Subt by 1s

Answers 1.OA.5.a


Add-Subtract

Answers 1.OA.5.b

Standard 1.OA.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).
Add Fluently

Answers 1.OA.6.a


Subtraction to Addition Strategy

Answers 1.OA.6.b

Work with addition and subtraction equations - Cluster 4


Standard 1.OA.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.
Compare Number of Shapes

Answers 1.OA.7.a


Compare Equations

Answers 1.OA.7.b

Standard 1.OA.8:  Determine the unknown whole number in an addition or subtraction equation relating 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 = ?.
Add Shapes

Answers 1.OA.8.a


Missing Numbers Subtract

Answers 1.OA.8.b