Pre-K · Operations & Algebraic Thinking
PK.OA.1: Basic add/subtract
PK.OA.1 is a Pre-K 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 Pre-K math learning standard
Demonstrate an understanding of addition and subtraction by using objects, fingers, and responding to practical situations (e.g., If we have 3 apples and add two more, how many apples do we have all together?).
In plain words
Basic add/subtract.
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
You see 4 birds sitting on a branch. 1 more bird flies to join them. How many birds are there altogether?
- 5
- 4
- 3
Where students can get stuck
Basic addition.
- Counting only the things that were added, so 4 blocks and 2 more gives the answer 2 instead of 6.
- Counting one finger twice while putting two hands together, so 3 fingers and 2 fingers come out as 6.
- Guessing the total from how big the pile looks instead of counting, so 4 grapes and 3 more becomes "ten."
Basic subtraction.
- Counting the things taken away instead of the ones left, so 4 grapes with 1 eaten gives the answer 1.
- Adding instead of taking away, so 5 crackers with 2 eaten becomes 7, because putting together feels more familiar.
- Counting every object again, including the ones moved aside, so 6 blocks with 2 taken off still gives 6.
Effective teaching strategies
- Act out a story with stuffed animals, such as 3 on the rug and 2 more arriving, and have students count all of them together to find the total of 5.
- Tell a story about 4 toy cars where 1 drives away, and have students count the cars still there and not the one that left.
- Have students hold up 2 fingers on one hand and 3 on the other, then touch each finger once while counting them all to find 5.
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.