Kids' Items to Place in an Estimation Jar

When filling an estimation jar, the possibilities are endless.

Estimation is an essential math skill that takes practice. Using an estimation jar allows children to refine this skill and better understand the concept of an educated guess. Teachers in lower elementary grades often let students take turns bringing an estimation jar home to fill and bring back to class. Estimating the quantity of the jar’s contents and then counting the exact number are excellent early math exercises in school or at home. However, parents often wonder what their child should put in that jar!

General Guidelines

It is important to make sure that whatever goes into the estimation jar is uniform in size. Objects that vary in size will make estimating difficult and could frustrate young and eager mathematicians. Avoid sharp or dangerous objects because kids are likely to handle whatever is in the estimation jar when they count the items. Try not to include very small items because young children will struggle to count more than 100 items.


As long as the teacher agrees, an estimation jar can be a wonderful way for your child to share a treat with classmates. Small, hard-shelled candy in different colors can be tasty items to estimate. For even more fun, think in terms of the season and use candy corn in the fall, mini candy canes in the winter or chocolate eggs in the spring. Any small candy will add excitement to an estimation lesson.

Nature in a Jar

Your backyard may be full of things to fill an estimation jar. Incorporating natural items in an estimation jar gives the opportunity to combine math and science into one lesson. Pebbles make good items for an estimation jar as long as they are relatively similar in size. Keep your child busy by sending them out to look for acorns or crabapples to fill the jar. Avoid items that are dirty or that may transmit disease, such as feathers.

Household Items

A number of items around the house work well in estimation jars. Coins are a particularly useful because counting them teaches kids about money as well as estimation. Paper clips, buttons and cotton balls are other options for filling an estimation jar. Colorful beads, seashells and superballs will make an appealing estimation jar as well. Have kids study the jar before making their estimates. Encourage them to count the items in the jar they can see to make an educated guess.