Ever since my son turned three he has been wanting to help me cook in the kitchen. The idea of him cooking with me in the kitchen was fun, sweet and appealing, but in actual practice it can be stressful, frustrating and test of my patience. I have been slowly getting better at letting go of my desire for perfection and cleanliness in the kitchen, so that I can be comfortable with him helping.

We’ve made lots of food together including pancakes, corn bread (his favorite!), cookies, cupcakes, etc…But, I recently realized that we’ve never made Rice Krispies treats together. Rice Krispies treats are one of my husband’s favorite snacks, they are one of the easiest foods for my son to help me cook in the kitchen, and we can learn a little STEM while making them! Win, Win Win! 🙂

Me and my kitchen helper

In this STEM for Kids activity I’m sharing how I turn a fun and easy recipe into a learning experience about measuring, counting, volume, and change of state! 

Let’s start by talking about the STEM involved in making Rice Krispies Treats.

 

Measurement and counting

In scientific experiments and calculations measurements are very important and must be exact. The same thing is true in baking. Learning to correctly measure ingredients for cooking is a great life skill in the kitchen and also great STEM preparation for future science classes.

As I let my son help me in the kitchen I always explain to him what ingredients we’re adding and how much. I tell him how and why we measure ingredients. Be sure to let your child do the measuring and counting how many cups of each ingredients they’ve added. I use any excuse I can to get my son to practice counting (see previous STEM for Kids posts), and this is another great way to make counting fun.

Volume

The Rice Krispies treats are a great example for learning about volume. Volume is the amount of space a three-dimensional object occupies. See the image of the cube below. The cube’s volume is calculated by its length (L) multiplied by its width (W) multiplied by its height (H).

Let’s apply the L x W x H concept to this experiment and engage our mom brains a bit…(I need this now that I’m a stay at home mom and don’t get to do too much technical thinking anymore)

Q: If we completely fill a 13 inch x 9 inch x 2 inch pan with the Rice Krispies treats, then what is the volume? And how many 2 inch cube treats will it make?

A: 13x9x2=234 cubic inches. 2 inch cubes have a volume of 2x2x2=8 cubic inches. 234/8=~29 treats.

This math is way too advanced for toddlers, but the more important message is for them to hear the word volume and explain to them that it is the space occupied by the Rice Krispies treats in the pan. They won’t completely understand, but it’s great to start introducing them to these STEM words and concepts are early as possible.

Change of State

Heating the marshmallows and butter causes them to change state from solid to liquid. Once all the ingredients are mixed together and allowed to cool the ingredients change state from liquid back to solid again, but in their new form. Pretty cool, right?!

My son loves watching the butter and marshmallows melt in the pan. As he watches them melt I explain to him what is happening: The butter and marshmallows change state as a result of an increase or decrease in heat (a form of energy). As heat is added the butter and marshmallows will melt. As the mixture cools, heat is removed and the melted ingredients solidify. In this case the marshmallows and butter are solidified in their new form mixed in with the Rice Krispies, forming the treats.

 

Let’s make Rice Krispies Treats!

This experiment is ideal for children ages 3+. By age 3 my son was finally ready to help in the kitchen with simple cooking, like this recipe.

Some steps in this recipe are safe for children to do alone, some steps can be done together, and some steps are for adults only. I have labeled each step in the recipe with Child, Adult, or Child and Adult to indicate who can perform each step.

Materials needed:

  • 6-7 cups Rice Krispies cereal (depending on how gooey you like your treats: less cereal=more gooey, more cereal=less gooey)
  • 5 cups miniature marshmallows (about 1 10oz bag)
  • 4 tablespoons butter
  • 1 cup measuring cup
  • 1 tablespoon measuring spoon (if using soft butter, rather than sticks)
  • 3 bowls (to separate ingredients)
  • 13” x 9” x 2” glass baking pan
  • cooking spray to grease the pan
  • 1 large saucepan or dutch oven

Safety:

Always monitor your child in the kitchen, especially when working with them near an open flame (on a gas stove top) or a hot electric cook top. Make sure before turning on the cook top that the child understands it will become very hot and not to touch the cook top or the pan that is being heated on the cooktop.

Procedure:

  1. Child: Measure out each ingredient (Rice Krispies, marshmallows and butter) and place in separate bowls. Set aside.

    Adding the butter (Note: we used soft butter, so had to measure it using a Tablespoon. If you use stick butter, just cut according to the markings on the packaging)

    Adding marshmallows. It is important to taste the marshmallows for freshness before adding them to the recipe. 😉

    Adding Rice Krispies

  2. Child and Adult: Spray the 13″x9″x2″ baking pan with cooking spray, set aside.
  3. Child and Adult: Add the butter to a large saucepan.
  4. Adult: Melt the butter over low heat.

    Watching butter change states from solid to liquid because of the heat

  5. Child and Adult: Pour the marshmallows into the large saucepan.
  6. Adult: Stir butter/marshmallow mixture constantly over low heat until the marshmallows are completely melted. Remove from heat.

    Watching the marshmallows change state from solid to liquid due to the heat

  7. Child and Adult: Pour the Rice Krispies into the large saucepan.
  8. Child and Adult: Stir the Rice Krispies mixture with a buttered wooden spoon or spatula until all the Rice Krispies are well coated. 
  9. Child and Adult: Use a buttered wooden spoon or spatula to press the mixture into the greased 13”x9”x2” baking pan.

    The best part of making the Rice Krispies Treats!

  10. Adult: Allow to cool before cutting into 2” cubes to serve.
  11. Everyone: Enjoy eating your homemade treats! 🙂

    The kids (and adults) tasted and approved this recipe!

What happened:

If you put in all the ingredients raw, you will have a trail mix like treat with the ingredients not binding together. The heat caused the butter and marshmallows to melt from solid to liquid. Melted marshmallows are very sticky, so adding the butter helps it not become too sticky. The sticky melted marshmallows bind to the Rice Krispies together to form the treats. When cooled the marshmallows and butter solidify in their new form in the Rice Krispies treat mixture.

If you’re doing this activity with older children you can further explore volume and change of state by answering these questions:

Do the raw ingredients occupy the same volume as the cooked Rice Krispies treats?

Add all the raw ingredients to the glass baking pan. Take a picture of how full the pan looks. After you’ve made the Rice Krispies treats compare the picture of the pan with the raw ingredients to how full it is with the cooked treats, does the volume appear to be the same? Why or why not? 

I hope you enjoyed this fun, easy and delicious STEM for Kids Activity. Does your child like to help you in the kitchen too?

Would you like to see more STEM for Kids activities on my blog? If you like this and my other STEM for kids activities I’ve done so far, let me know in the comments below so I know if you, my readers, would like to see more of this or not. Thanks for your help and feedback!

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