# Marker Estimation Jars

These are the estimation jars I had in my classroom math center recently. Our school library (in a PreK-8th grade school where I once taught) there was an estimation jar with a lot of little items in it, such as jelly beans. It wasn’t not easy even for me to estimate  a big jar full of jelly beans or candy corn, so I don’t know how young children could even begin to estimate the amount.

Here’s how I made estimation jars for Pre-K that will make more sense to the children. I made four jars:

• The first jar had one marker in it with a numeral 1 taped to the front.
• The second jar had three markers with a numeral 3 taped to the front.
• The third jar had six markers with a numeral 6 taped to the front.
• The last jar had ten markers with a question mark taped to the front.

This way, the children can see what one marker looks like in a jar, what 3 looks like, and what 6 looks like. They can then use that visual knowledge to estimate how many are in the last jar.

I placed a basket of recording sheets beside the jars for the children to write their guesses. (Download link to the recording sheets below.) After everyone has had an opportunity to guess, we will count the markers in the last jar during our large group time.

I’m planning to put different items in the jars each month, so the children will have a lot of practice during the year. I know someone will ask: the jars I used came from Walmart (kitchen area) and they are clear plastic. The lids fit on with a rubber seal so they don’t come off too easily.

This was a first attempt. Hopefully with practice, their guesses will get better.

## More to estimate:

• Straws
• Pinecones (make sure they are approximately the same size)
• Tree nuts (pecans or other)
• Bouncy balls (like the kind from gum machines)
• Gift bows (great at Christmas)
• Candy canes (also Christmas)
• Bear counter manipulatives
• Unifix cubes
• Plastic eggs (great at Easter)
• Paintbrushes
• Marbles
• Cube dice
• Small fruit, such as kiwi

Karen is the founder of PreKinders.com. She also works as a full-time Pre-K teacher in Georgia.

1. Maria says:

Wow! I like this, I’m going to try this project w my kids in our daycare! Thank u!

2. Therese says:

What a great way to teach estimation, counting, one on one, work on fine motor and problem solving. Are the jars glass? I really llike this concept. Thanks for sharing!
Therese

• Karen says:

Thanks, Therese! The jars are plastic. They are sold at Walmart in the kitchen area.

3. Jennifer says:

Love it!! Thanks! What a super way to make estimation more meaningful!! Love the site and your ideas. Thanks for all you do.
Jennifer

4. Danya says:

I am loving all of these ideas, this year the curriculum is my responsiblity and trying to find things that will work for two Pre-K classes, total 42 kids of all levels has sometimes been overwhelming. Thank you for all you do.

5. Linda says:

Thanks for sharing such a lovely idea.You are right,this way estimation is more meaningful. I am going to try this with my Nursery 3 year old students.=)

6. Indrani Mukherjee says:

These will work wonders i am sure. Thanx for sharing these with us.

7. RACHEL says:

ill try this in my class i like the aspect of guessing it ‘ll make our class intereactive

8. LaQuetha says:

I can’t wait to try this with my class this is very exciting. I having been trying to think about estimation for a while now.

9. Debbie says:

This is a great idea! My students have no experience “writing” digits yet. What would you suggest?

• Karen says:

Hi Debbie, Neither do mine, actually. You might want to just put 9 markers in the last jar instead of 10. Since this was early in the year, I just let them practice writing on the sheets and didn’t worry about how correct they were. It was a good portfolio piece to save because I could see who was able to form a number, who made a number-like symbol, and who just made linear writing. I also made a chart on chart paper: I wrote each child’s name on it, asked them their guess, and wrote the number myself beside their name. I had several children come close to the right amount, and one child who guessed 10! I will post a picture of the chart soon.

10. Maria says:

This is a great site with so many useful tips and tools. Thank you for the information you provide for everyone to read and use.

11. aleyce says:

Hi Karen.
I am a student working on my Master’s Degree in Early Childhood Education and I teach preschool children. I want to thank you for sharing your ideas.

Aleyce

12. jayme says:

Many of my 3s and 4s are not able to write their numbers yet either. They can, however, count the dots and equate it to a number below. I think I might try to write a number and then put that number along with pictures of the item we are estimating beside it. They can circle or mark on the answer they would like to guess. Since they can count numbers of children allowed in each center by counting the numbers of children depicted on the sign I think this will work. Thanks for the ideas!
Example:
1 one *
2 two * *
3 three * * *

• Karen says:

Hi Jayme! Most of mine don’t write numbers yet, either. (I just let them try when I did this activity.) I love your idea, though — great idea! Thanks for sharing it with me & other readers here!

13. Sheri says:

I like this idea! One year I sent home a “guessing jar” with a different child each week and had the parents put 1 to 10 items in it (and not tell their child how many). For the jar I used one of those plastic barrels cheese balls come in. I put the directions on the lid so the parents would remember what it was for. It always came back the next day…the children were excited about their stuff being in the jar! I haven’t done it in a while, so maybe I will start with your idea and see where it goes!

• Karen says:

What a fun idea, Sheri! Thanks for sharing! I’ll have to try that, too.

14. Deirdra Trawick Belton says:

OMG so much fun, and a fantastic way to put the estamation guessing game on the Pre-K level

15. ANA RURH says:

I’m going to try this project with my kids in our daycare! I have my assesment coming up and this is a great way to teach the kids. Thank for sharing
Ana

• Karen Cox says:

Thanks, Ana! Glad it’s useful to you.

16. Mummysideas says:

Fantastic ideas so glad you shared it is so useful kids love it thank you x