Skip to main content
Common Core MathKindergartenOperations & Algebraic Thinking

K.OA.2: Solve Word Problems Within 10

Also written as K.OA.A.2 and CCSS.MATH.CONTENT.K.OA.A.2 · Cluster: Understand addition as putting together and adding to, and understand subtraction as taking apart and taking from.

Make Word ProblemsAll 22 Kindergarten Math Standards

The Official Wording

Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.

Common Core State Standards, Kindergarten, Operations & Algebraic Thinking · Read it at the source · Checked October 14, 2026

What K.OA.2 Means in Plain English

Kindergartners hear a short story with numbers in it and work out the answer with counters or a drawing. Six ducks on the pond, two swim away: put out six counters, slide two aside, count four. The totals stay at 10 or below so the model stays easy to build.

The hard part is deciding whether the story is a joining story or a taking-away story, so acting it out matters more than the arithmetic. In 1st grade the numbers grow to 20 and the unknown can be anywhere in the equation, like 4 + ? = 9 (1.OA.1).

K.OA.2 I Can Statements

  • I can use counters or a drawing to solve a story problem.
  • I can tell if a story is about adding or taking away.
  • I can add and subtract numbers within 10.

K.OA.2 Worked Example

One taking-away story solved the way the standard describes, with counters first and the equation last.

Problem

Six ducks are on the pond. Two ducks swim away. How many ducks are still on the pond?

Six ducks, two swim away
  1. Listen for what happens. Ducks leave, so this is a taking-away story.6 ducks, 2 leave
  2. Put out one counter for each duck at the start.6 counters
  3. Act out the story: slide the two ducks that swim away to the side.4 counters stay, 2 pushed aside
  4. Count the ducks still on the pond.1, 2, 3, 4
  5. Say the story with numbers, then write it.6 - 2 = 4
Answer4 ducks are still on the pond

Check it: Bring the two ducks back: 4 and 2 more is 6, the number you started with.

Common Mistakes with K.OA.2

Adding every number in the story

“Six ducks, two swim away” answered with 8

Try this: Act the story out with counters before any number is written, and ask whether there are more ducks or fewer now.

Answering with the number that was taken away

Slides two counters aside and announces “2!”

Try this: Point back to the question after the counters move: how many are still on the pond, not how many left.

Drawing that takes over the math

Six beautifully detailed ducks, ten minutes gone, and no answer

Try this: Model quick math drawings in front of the class: a circle is a duck, a cross through it means it left.

Where K.OA.2 Fits

Comes BeforeK.OA.1Show adding and taking away with objects, fingers, drawings and equations.K.CC.5Count out a given number of objects.
AlongsideK.OA.3Break a number up to 10 into two parts.K.OA.4Find the partner that makes 10.
Comes NextK.OA.5Add and subtract within 5 from memory.1.OA.1Solve word problems within 20 with the unknown in any position.1.OA.6Add and subtract within 20 with strategies like making ten.

Practice K.OA.2

Word Problem GeneratorFree ToolKindergarten story problems within 10, adding and taking away, one short story per box with space to draw the counters.KindergartenWithin 10Add and subtract
Make Word Problems
Math Worksheet GeneratorFree ToolPlain addition and subtraction within 10 for the second half of the standard, with pictures to count under each problem.KindergartenWithin 10Answer key
Make a Worksheet

Quick Check

  1. There are 4 apples in the bowl. Mom puts in 3 more. How many apples are in the bowl now?
  2. Nine children are on the bus. Five get off. How many children are still on the bus?
  3. Kai has 2 red balloons and 6 blue balloons. How many balloons does Kai have?

K.OA.2: Other Names

K.OA.2K.OA.A.2CCSS.MATH.CONTENT.K.OA.A.2

Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved. Official wording from the Common Core State Standards PDFs at corestandards.org, last checked October 14, 2026. The explanation, I can statements, example, mistakes and practice on this page are EMStudio’s own, written beside the official wording. They are not part of the standard.