Wednesday, April 29, 2020

Estimation Jar

Estimation is a necessary life skill that can help us function successfully in today's world. The Estimation Jar can assist all ages in developing this skill in a fun-filled way, whether at school, homeschool, or just as a home activity. This activity is Justice Family tested  - and approved!

Are you good at estimating? This fundamental skill can be developed through practice. I have used the Estimation Jar activity when I taught First Grade, and they loved it. I also used this activity in Grades 3 and 4, and it was a favorite part of the day there, also. Now that I am Homeschooling grandkids, I have an Estimation Jar again. This time, however, we asked the adults to join in the fun.

Getting Started

First, you need an unbreakable jar. We are using a clean plastic 28 oz. peanut butter jar.

Next, set rules and guidelines. Here's our rules:

  • 10 to 100 objects in the jar
  • Objects must be clean.
  • Anything edible must be wrapped.
  • Objects in the jar must be the same size.
  • Keep a list of what has been estimated.


One person counts objects, writes the number in a hidden place, and places the objects in the jar. 

Ms. Nancy's Tip:  A good place to write the number is on a small paper that is taped upside down on the underside of the jar lid. 

Everyone looks at the jar and writes an estimate on a small paper or card. DO NOT allow anyone to count the objects!

The person who filled the jar looks at everyone's estimate and reveals the actual number.

The person who is closest to the actual number gets to fill the Estimation Jar  next time.

Possible items to fill the jar:

Nails by Papaw
  • pennies
  • nails
  • pompoms
  • crayons
  • tiny bears
  • small toys
  • small game pieces
  • buttons
  • toothpicks
  • marbles
  • Etc.

How many bears do you think are in the jar?

Ready, set, estimate!


  1. Wow! Can you please do like a whole set of estimation in the bears like a specific type of quantity on this jar and then on this and etc.

    1. You could use 2 jars of the same size. Put a certain number of bears in 1 jar and label it with the correct number. Now add a different quantity to the other jar and ask how many are in this jar. The sky is the limit! Have fun!