Subtracting fluently within 5
In kindergarten, children learn to subtract within 5 quickly and accurately, such as 5 - 2 = 3 and 4 - 1 = 3, without counting back every time.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
Try these with your child
These are real questions from our kindergarten practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
2 ducks are in a pond, and 2 swim away. How many ducks are left?
- 0
- 4
- 2
Why this matters
When your child knows that 5 take away 2 leaves 3, subtraction stops being slow counting and starts to feel like something they own. Knowing these facts by heart frees your child from counting back, which is easy to slip on, and leads to subtracting fluently within 10 in 1st grade. They also come up whenever something is shared, eaten, or put away, like 4 crayons with 1 lost under the couch.
If these facts are slow to come, your child can review adding fluently within 5, since each take-away fact has an adding partner.
Where kids can get stuck
- Mixing up a subtraction fact with its adding partner, saying 4 - 1 = 5 because 4 and 1 go with 5.
- Counting back and including the starting number, so 5 - 2 becomes "5, 4" and the answer comes out as 4.
- Saying the number taken away instead of the number left, so 5 - 4 is answered as 4 rather than 1.
How you can help
- Put 5 grapes on a plate, let your child eat 2, and ask how many are left before they count. Change the number of bites the next time grapes come out.
- Start with 5 buttons, roll a die, and take away that many. Ask your child to say how many are left before you check, and roll again on a 6.
- Ask a quick take-away question in the car, such as "There are 4 of us. If 2 get out at the store, how many stay in the car?" Let your child picture it and answer.
Want a little more? Watch the kid-friendly video below together, or try Bobby's Math Club for free practice that adapts to your child.
Kid-friendly explanation
Questions parents ask
How can I tell if my child knows a fact or is still counting?
Watch the moment before they answer. If the answer comes before any fingers move, or they say something like "because 2 and 3 make 5," they know it. If they count back on their fingers, they're still building it, and that's fine. Ask how they knew, and celebrate the facts they know by heart.
Is it common for subtraction facts to take longer than addition facts?
Yes, and that's okay. Adding moves forward, which feels natural, while subtracting asks your child to work backward. Help by pairing each fact with its adding partner. If they know 3 + 2 = 5, ask what 5 take away 2 leaves, and let them notice that the same three numbers belong together.
What about taking away zero, or taking away everything?
Facts like 4 - 0 and 4 - 4 can feel odd at first. Taking away nothing leaves the group as it was, so 4 - 0 = 4. Taking away everything leaves nothing, so 4 - 4 = 0. Act them out with crackers: eat none, then eat them all. Once your child sees the pattern, these become some of the easiest facts to know.
Make learning math fun
Bobby's Math Club turns kindergarten math practice into something fun to do together.
- Free, unlimited practice for every child in your family
- Practice that starts where your child is and grows with them
- Hints when they are stuck, and a celebration when it clicks
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.
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Join the clubNote for teachers: This skill is covered by Common Core math standard K.OA.A.5: “Fluently add and subtract within 5.” Learn how Bobby's Math Club can help your students grow. (Common Core K.OA.5)