1st Grade · Operations & Algebraic Thinking
1.OA.A.2: Solve word problems that call for addition of three whole numbers
1.OA.A.2 is a 1st grade Common Core math standard in Operations & Algebraic Thinking. Here’s what it really covers, and how you can help your students learn it.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
The standard
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.
In plain words
Solve word problems that call for addition of three whole numbers.
Sample questions from student practice
These questions from Bobby's Math Club are the kinds of questions your students will see. You can try answering them to see what a student might see.
Question 1 of 3
Mia has 3 red apples, 2 green apples, and 4 yellow apples. How many apples does Mia have in all?
- 10
- 7
- 9
Where students can get stuck
- Adding the first two numbers and stopping, answering 7 for "4 ducks, 3 geese, and 6 swans" instead of 13.
- Skipping or repeating a number when counting all three groups from 1, usually while moving from one group to the next.
- Adding strictly left to right and missing easier routes, like spotting that 7 and 3 make 10 in 7 + 5 + 3.
Effective teaching strategies
- Draw three groups in three colors, such as 4 ducks, 3 geese, and 6 swans, and have students find the total only after all three groups are drawn.
- Have students cross out each number as it is added into a running total, so no group is skipped or counted twice.
- Give problems like 7 + 5 + 3 and ask students to look first for two numbers that make 10, then add the third number to that ten.
Units that teach this standard
Find where 1.OA.A.2 lands in the program you teach. Each unit has a guide written for families. Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence.
Bridges in Mathematics
enVision Mathematics
Everyday Mathematics
i-Ready Classroom Mathematics
Illustrative Mathematics
Reveal Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Story problems that add three numbers for a plain-language look at this skill, with three questions to try together and ideas for helping at home.
Help every student practice problem solving at home
In Bobby's Math Club, students practice at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free for every family.
See how it works for teachers
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.