Thinking Blocks Interactive Tutorials – Model and solve word problems with addition and subtraction. Online interactive tutorial. First and Second Grade.

How to use Thinking Blocks Tutorial

**Online Addition Word Problems and Missing Addend **

Word Problem Set 1

Word Problem Set 2

Word Problem Set 3

Word Problem Set 4

Word Problem Set 5

Word Problem Set 6

Word Problem Set 7

Word Problem Set 8

Word Problem Set 9

Word Problem Set 10

**Online Addition Word Problems with 3 Whole Numbers **

Word Problem Set 1

Word Problem Set 2

Word Problem Set 3

Word Problem Set 4

Word Problem Set 5

Word Problem Set 6

Word Problem Set 7

Word Problem Set 8

Word Problem Set 9

Word Problem Set 10

**Represent and solve problems involving addition and subtraction.**

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.

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.

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

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.)*

Understand subtraction as an unknown-addend problem.

*For example, subtract 10 – 8 by finding the number that makes 10 when added to 8.*

**Work with addition and subtraction equations.**

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.

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 = _*.

**Represent and solve problems involving addition and subtraction.**

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.