Take a short nature walk and collect ten acorns & ten pinecones. Rocks, sticks, or flowers will work too! Lay the collection on the ground or table and ask your child which has more. Your child may think that there are more of the bigger item. Match each pinecone to one acorn to prove you have equal amounts.
One important stage in your child's math development is the understanding that the total number of objects does not change just because those objects are moved around and rearranged. That may sound obvious to you, but it isn't necessarily obvious to your preschooler! For example, if five pennies are laid in a row close together, a child will likely be able to tell that there are five coins. However, if the same five coins are then spread further apart in a longer row, a child who does not yet have "number conservation" will think that there are now more coins in the row. You can help your child by counting together while touching each object one time as you say the next number. Then ask your child how many total items there are in the group. Your child will soon recognize that the last number stated while counting represents the total number of items in a group.
Talk about where acorns and pinecones come from. Look for the oak tree that dropped the acorns and the pine tree that gave you pinecones. How are the trees the same, and how are they different? Sketch a simple picture of each one in your journal.
This concept might be too difficult for young children. Instead, collect acorns at your local park and count them together. You can help your child “keep track” while counting the acorns by removing an acorn once it is counted. This will prevent counting in circles.
Include another item to compare to the pinecones and acorns, such as leaves. Children are often amazed that something in a small pile (such as leaves or acorns) can have the same number of items as something in a big pile (such as the pinecones). Experiences like this will help them grasp this concept.
“Acorns Everywhere” by Kevin Sherry
Estimate how many acorns it would take to measure the length of a pinecone. Try it out! How many acorns will it take to equal two pinecones?