Here’s a fun STEM challenge that is perfect for Valentine’s Day. Challenge kids to use building toys from around the house to build a heart! We had fun exploring how many different ways we could build a heart with the things we had at home.

Grab LEGO bricks, MagnaTiles (or similar), toothpicks, etc. We even used our wooden train track to build a heart!

I would recommend this activity for preschoolers up through second or third grade. Building hearts was just the right difficulty level for my 7 year old. She could do it without help, but did need to think about it and work to figure out the design.

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Pattern Blocks Heart

We love using pattern blocks for all kinds of math activities.

Kids will probably approach this project in different ways. It would be fun to do this with a class and discuss the different ways that the blocks can be used to make a heart.

LEGO Hearts

Well, of course we used LEGO bricks to build a heart! Build a heart that can stand up, like the ones in the picture. Or, build a heart mosaic on a base plate. Make the hearts a solid color or a mix or colors. So many options here! These make great decorations once you are finished.

MagnaTiles Heart

You can use MagnaTiles, or any other brand of magnetic tiles. This is one of our favorite building toys! We have both MagnaTiles and Magformers, but the MagnaTiles get played with the most. The kids use them to build little houses for tiny toys like Safari Toob animals or LEGO figures.

MagFormers Heart

We built a heart with Magformers too! As I said above, MagnaTiles are our favorite, but Magformers are still a great toy, and probably more durable.

Toothpick and Marshmallow Heart

We had a lot of fun with this heart-building project! I had a little container of multi-color toothpicks, so Janie sorted out all the red ones to make our hearts.

Janie (7) built the heart on the left all by herself, copying my design. We broke some of the toothpicks in half to get shorter segments.

You can easily keep and display your toothpick hearts. The marshmallows will harden and hold the toothpicks together very well! Of course, you’ll eventually need to throw them away…

Wooden Train Heart

This one might be my favorite! We wondered if we could build a train track in a heart shape, and we COULD! So cool!

Now, you can’t drive the train all the way around the track in this configuration – the loop doesn’t work. But it was very fun to build! Janie added on track in the center and at the bottom of the heart to make more places to go.

Thinking through how to make the track into a heart takes some good critical thinking skills!

Have fun building hearts!

Need more Valentine’s Day activity ideas?

Make some adorable Clothespin Airplane Valentines – such a fun craft.

Kids will also enjoy building a LEGO Valentine Box. There’s an option to give it a mechanical opening letter slot!