K.OA.1: Show Addition and Subtraction
Also written as K.OA.A.1 and CCSS.MATH.CONTENT.K.OA.A.1 · Cluster: Understand addition as putting together and adding to, and understand subtraction as taking apart and taking from.
The Official Wording
Represent addition and subtraction with objects, fingers, mental images, drawings, sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.
Common Core State Standards, Kindergarten, Operations & Algebraic Thinking · Read it at the source · Checked October 14, 2026
What K.OA.1 Means in Plain English
Kindergartners show what adding and taking away mean before they are asked to be quick. Three birds on a wire and two more land: hold up three fingers then two more, clap three times then twice, draw it, act it out, and write 3 + 2 = 5.
The equation is the last representation, not the first, and children spend weeks on fingers and drawings before it means anything. Solving word problems within 10 (K.OA.2) uses these models, and in 1st grade they stretch to word problems within 20 with the unknown in any position (1.OA.1).
K.OA.1 I Can Statements
- I can show adding with my fingers, objects or a drawing.
- I can act out taking away and tell what happened.
- I can write a number sentence that matches my picture.
K.OA.1 Worked Example
One addition story, 3 birds and 2 more, shown five ways and ending with the equation, which is the order the standard lists them in.
Three birds sit on a wire. Two more land. Show how many birds there are now.
- Fingers first: three on one hand, then two more on the other, and count them all.3 fingers and 2 fingers, 5 in all
- Counters: push three red counters together with two blue ones.3 counters + 2 counters = 5 counters
- Sounds: clap three times, pause, clap twice. How many claps?clap clap clap, clap clap: 5
- Draw it: three birds on a line, two birds flying in, and count the birds.a drawing of 5 birds
- Say it, then write it: three and two more makes five.3 + 2 = 5
Check it: Take two birds away from the five and you are back to three: 5 - 2 = 3. The story runs both ways.
Common Mistakes with K.OA.1
Counting only the new group
Three counters, two more pushed in, and the answer is “2” because only the new ones got counted
Try this: Have the child count the whole set once from the start after joining the groups, and say the last number as the answer.
Reading 3 + 2 = 5 as three separate numbers
The child writes 3 + 2 = 5 correctly but cannot point to the five birds in the picture
Try this: Match every symbol to the picture out loud: the 3 is these birds, the + is the landing, the 5 is all of them.
Taking away means taking all
Five counters, “take away two”, and the child sweeps all five off the table
Try this: Act it out with children as the birds: five stand, two sit down, and the class counts who is still standing.
Where K.OA.1 Fits
Practice K.OA.1
Quick Check
- Show 4 + 1 with your fingers. How many fingers are up?
- There are 5 cups on the table. Take 2 away. Write what happened as a number sentence.
- Clap 2 times, then clap 3 more times. How many claps was that altogether?