# Colorado - Grade 1 - Math - Operations and Algebraic Thinking - Adding Three Whole Numbers - 1.OA.2

### Description

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.

### Additional Info

• State - Colorado
• Standard ID - 1.OA.2
• Subjects - Math Common Core
• Grade - 1

### Keywords

• Math
• Colorado grade 1
• Operations and Algebraic Thinking

## More Colorado Topics

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.

Express the length of an object as a whole number of length units, by laying multiple copies of a shorter object (the length unit) end to end; understand that the length measurement of an object is the number of same-size length units that span it with no gaps or overlaps. Limit to contexts where the object being measured is spanned by a whole number of length units with no gaps or overlaps.

Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.

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).

## Here is the skill that Colorado requires you to master

• Grade Level 1
• State Test CMAS PARCC
• State Standards The Colorado Public Standards (CAS)
• Subject Math
• Topic Name Adding Three Whole Numbers
• Standard ID 1.OA.2
• Description
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.

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### Colorado schools will administer the CMAS PARCC assessments

Colorado schools will administer the CMAS PARCC assessments to measure student proficiency of the Colorado Academic Standards (CAS). Education Galaxy’s CMAS PARCC test preparation program provides online assessment and practice for students in Grades K-5 to help build mastery towards the Colorado Academic Standards. Our unique online program is easy to use and enjoyable for both teachers and students. Students work on their Study Plans practicing important concepts while teachers pull formative assessment reports to identify the strengths and weaknesses of their classroom and individual students.