Monday, April 11, 2011

One-to-One Correspondence

Great book for this lesson!

If your child is already in preschool or has started kindergarden, then chance are, you have heard the term "one-to-one correspondence" before. Maybe it's been listed on their Skills Accomplished list or Report Card.

It is usually explained as the ability to match one object to one (corresponding) number or object.

Example: 1 egg per egg carton holder. 12 total.
Example: 2 socks to 2 shoes.

This concept is so fundamental that we often don't even think about it. Most people want to jump right into teaching their kiddos to count 1-10. While Rote learning (memorizing counting numbers) is a handy tool, it can just be like singing a song and have no meaning to them. In order to lay a strong foundation for mathematic understanding they need to fully understand the meaning behind each of those little ol' numbers!

Children (all people really) learn best by using concrete examples, hands-on and FUN learning!

There are so so many ways to practice this concept for all developmental levels and can be as simple as:
  • Count your fingers and toes (touching each of them).
  • Count all of the animals in a book.
  • Covering the numbers 1-5 with the corresponding amount of stickers.
  • Counting the trees or cars you pass on a walk!
Teacher Tip- 3 techniques to help teaching this concept:
  1. Scanning- Have your child move their hand over the object as you count out loud. Better yet...touch it!
  2. Organize- If the items are scattered about you can move them together. Once counted, you can move them into a line or in an organized shape. Your child can then go back if they lose track, reorganize their thoughts, and pick back up.
  3. Partition- Assign separate "compartments" for all objects, counted and not yet! Like egg cartons, cups, baskets, paper cut into different shapes labeled with a number.
Do NOT let this explanation scare you. Most likely you are already doing these things and you hadn't even thought about it! See you are a teacher!

Here is an example of us playing (and secretly practicing 1-to-1 correspondence yesterday).

See that isn't scary!

And do not let these two pictures fool you. This lasted all of about 3 minutes!

There are so many ways to practice this! Here are some from a quick google image search:

What other ways do you practice this concept? Please share!


  1. Neat explanation Sarah, and some lovely ideas, thank you!

    I like to make story problems too. Are there enough hats for the teddies to have one each? And we look at the group of hats, the group of teddies and have a guess. Then we match them up one to one to find out for sure.

  2. Nice job sharing fun ways to teach an important concept!

  3. Book Chook- Story Problems are great! What a perfect example! Thank you for sharing!!

    Michelle- Thank you!

  4. I love the way you break this down. I love when experts can bring a little applicable theory into everyone's life! I also agree about using manipulatives and play to get at the complex concepts underlying the rote memorization! We do a lot of the activities you mention in one form or another.

  5. Great explanation and practical too. My son is really good at rote counting but he's just starting to apply 1:1. He's only 2 and I read an article from Parents as TEachers that said they can usually match 1:1 and count up to their age- so 2 year olds can count 2 object w/o loosing track, 3 year olds can count 3 objects. I guess at some point they make the jump to being able to count multiple objects. I found that piece of information interesting- guess I'm a nerd too :) Thanks for sharing these activities. We always need more math stuff.

  6. How cool! We discussed this recently on the twitter tweet chat for homeschool math (#HSMath -

    One to one correspondence is an advanced abstract algebra concept. This means that it is one of the primary building blocks of our number system and is perfect for kiddos. I wish we could incorporate more of these into learning - both in homeschool classrooms and public school classrooms.

    (pondering some posts now...)

  7. Hi Sarah,

    I just found your post while doing some research for a post of my own on this very topic. I read in another article that one-to-one correspondence is not only about matching pairs, but also comparing sets (comparing which set has more and which less). Would you agree with this? Would love to hear your thoughts.

    Glad to have found your blog. I can't wait to have a look around.

    Take care,

  8. Hi Georgia!

    I'm so glad you found us on here! I am love finding more and more teaching blogs! I have a serious addiction! :)

    I do agree that comparing sets uses one-to-one correspondence! To compare sets the Counter needs to be able to correspond matching items to see how many are "left over" or are "missing." Then they will be able to physically see which set is greater than or less than.

    So many match concepts are learned in that activity!

    What do you think!

    Thanks for stopping by! I'm about to dive into your blog!! I can't wait!


  9. Thanks so much Sarah!! What started out as a quick post, has turned into a research project!! I have a tendency to do that with any subject matter I tackle. I have linked to you in the post and will let you know when I publish it...hopefully today or tomorrow.

    Have a super day!

  10. Oh thanks! I look forward to reading it!

    By the way, I'm shocked you could understand my last comment...I think lack of sleep was hitting me at nap time. Sorry for the misspelling and poor grammar! Ha ha!


  11. Hi Sarah!

    Thank you so much for stopping by my blog. I would love to respond to your comments by email, but cannot find it here. Would you mind sending it my way. You can email me at

    I have just posted my article on one-to-one. Here's the link:

    Thank you again for your feedback!

    Take care,
    Georgia :)

  12. Thank you for sharing your premath ideas today - how appropriate for Teaching Preschoolers!



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