Addition Fun! Creating a homemade calculator

Sharing is caring!

This fun homemade calculator will encourage your child to learn simple addition while creating a chute for all the items you’ll be adding together!

Introducing simple addition concepts to a child builds a bridge between a number and a quantity by using numbers they have learned and assigning them to quantities in everyday life. It also teaches the concept of combining two numbers to create one large number.

For this math experiment, we are starting with small numbers so it doesn’t get overwhelming for them. We will be using the numbers 1 through 5 for each chute, so 10 objects in total to add together.

Be sure to meet your child where they are at. If they are having difficulty counting, lead the way in counting how many pom-poms you are adding together. The last thing you want to do is overwhelm and frustrate them when you are attempting to have fun with a math experiment.

Homemade calculator math experiment

How to make the Addition Fun! math experiment

Supplies you will need

For the Addition Fun experiment, you’ll need:

  • Two empty toilet paper rolls
  • Tape
  • 10 Pom-poms (or any small, light object)
  • Marker
  • Optional: plastic bin, pizza box, or something similar to tape toilet paper rolls to and catch the pom-poms, otherwise you can use the wall)

Before you start

Before beginning each calculation, have your child count the number of pom-poms in each of the two piles (if they are able). Or, if your child has counting down already, you could have them choose the two numbers to add together and pull that number of pom-poms to create the piles.


Here is how to do the Addition Fun experiment with your child:

Step 1: Tape roll at a diagonal to the wall or optional container

Simply use two pieces of tape on the toilet paper roll to place it diagonally on the box

Keep the sticky side of the tape out and fold it into a roll. Do this twice, and place both pieces of tape on one of the toilet paper rolls.

Press the toilet paper roll firmly onto the backing that you chose. In my case, I pressed the rolls onto the box.

Get your preschooler involved: If your child enjoys painting, have them paint the rolls before taping them.

Step 2: Tape the second roll at a diagonal to the first roll

Showing the two toilet paper rolls at a diagonal and combining at the bottom

Repeat step 1, but be sure to place both rolls at a diagonal from one another. It provides another visual that we are taking two numbers and combining them into one number.

Step 3: Draw a “+” sign between the two rolls

If you ended up taping your toilet paper rolls to the wall, a simple solution here is to place two pieces of tape in a + shape on the wall and draw on the tape.

I wouldn’t want you to draw on your walls!

Get your preschooler involved: Draw a + sign and see if your child can recreate it!

Step 4: Briefly explain how adding together quantities works, then start having fun!

Showing my child how the experiment will work by using our hands to add together numbers

Something we like to do in our house is to show how to add using our hands.

We hold up the first number we want to add on one hand and the second number on the other hand, then bring our hands closer together to count the result.

Since that is how we do it in our house, I decided to explain our calculator to her in that way (you’ll see me doing that in the video and her repeating it).

Once they understand how it works, start creating piles of pom-poms (or whatever object you decided) to begin adding them together!

The math behind the Addition Fun! experiment

Addition Fun! gives a visual to how to add together two numbers and create a larger number. It also gives you the opportunity to talk about quantities.

How it works

In this experiment, we are adding together two numbers. To keep things simple, we are only using 10 objects so our end calculation only goes to the number 10.

This homemade calculator is showing how two separate numbers can be combined to make one larger number. It allows your child to see how quantities work with a real-life example.

Before beginning the experiment, show your child the two different numbers of objects separated. If they are able, have them count the number of pom-poms in each pile.

Then ask, “do you think we will get a larger number or smaller number if we combine these two piles of pom-poms?”. This will get them thinking about the process of combining or adding one pile to another pile.

This simple experiment gives a visual to adding two quantities together as well as adding a playful aspect by shooting pom-poms down the toilet paper rolls!

More math experiments to try out with your child

FAQ about the Addition Fun! experiment

Can you use this same concept for subtraction?

You can, but it will look slightly different. If you want to build a homemade calculator built for subtraction, one idea is to tape velcro to the top of your calculator. Choose your number to subtract from and place that number of pom-poms against the velcro. Then, remove the number you want to subtract and send it down the chute. How many are left against the velcro?

Should I do Addition Fun! if my preschooler can’t count?

Definitely! This experiment is a great opportunity to teach counting while incorporating addition into it. Use every opportunity possible to count out your numbers: count the two separate numbers you are going to be adding, count the end result, even count as you’re placing pom-poms down the chute. If your preschooler is still having a hard time counting, do not bypass this experiment. Simply take your time working through the numbers and see if this new way of counting is a method to drive home counting!

Recent Posts