Kindergarten · Operations & Algebraic Thinking
K.OA.A.1: Represent addition and subtraction
K.OA.A.1 is a kindergarten 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
Represent addition and subtraction with objects, fingers, mental images, drawings, sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.
In plain words
Represent addition and subtraction.
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 6
There are 3 birds on a branch, and 2 more birds fly to join them. How many birds are there now?
- 5
- 2
- 3
Where students can get stuck
Represent addition.
- Copying 3 + 2 = 5 correctly, but not being able to show the same problem with objects or a drawing.
- Holding up fingers for each number but not putting them together, so 4 + 1 is answered as "4 and 1" instead of 5.
- Drawing every part of a picture in careful detail, so 4 cats and 2 more takes so long that the adding gets lost.
Represent subtraction.
- Drawing a subtraction problem as two separate groups, such as 5 circles and 2 circles, instead of crossing out 2 of the 5.
- Reading the minus sign as plus, or adding both numbers whatever the sign says, so 6 - 2 becomes 8.
- Writing the numbers in the wrong order, such as 2 - 5 = 3, for a story about 5 frogs with 2 hopping away.
Effective teaching strategies
- Act out 3 + 2 with students themselves: three stand, two more join, and the class counts everyone to find the total of 5.
- Read each sign aloud with students as plus or minus, and match it to an action, such as put together or take away, before they show the problem.
- Draw 5 circles and cross out 2 to show 5 - 2, and have students tell how many are left, so subtraction looks like one group getting smaller.
Units that teach this standard
Find where K.OA.A.1 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
Math Expressions
Saxon Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Each skill has its own guide for families, with a plain-language look at the skill, 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.