A good baker needs to understand fractions
When I was younger, I loved helping my mother make waffles from scratch on weekend mornings. I became quite adept at filling up the flour right to the very edge of the cup to make sure our measurements were just right. I even remember learning the difference between a teaspoon and a tablespoon. But one day, my mother told me we were going to double the batch of waffle batter. How was I supposed to figure out two times 1/3 cups? And if I was going to double a half teaspoon, could I just put in one whole teaspoon? Would that be the same amount? These were real, difficult questions whose answers would have a real impact on the outcome of my waffles.
This set of lessons uses baking as a hands-on way to teach students how to understand, compare, and work with fractions in a real-life situation. In the first lesson, students use measuring tools—such as whole cups, half cups, quarter cups, third cups, tablespoons, and teaspoons—to measure ingredients like flour and sugar. Along the way, they learn to identify common fractions, including 1/8, 1/4, 1/3, 1/2, and 1/1, in both cup and spoon measurements. This practical knowledge is further applied in the second lesson when they double and triple a cookie recipe to practice adding and multiplying fractions. They will also explore the relationships between measurements, such as how many tablespoons or teaspoons equal 1/4 cup. Finally, in the third lesson, students will bring in a recipe and are challenged to identify and compare fractions.
Half the joy of baking with children lies in their excitement and enthusiasm; the other half is watching them tackle a real-world challenge, follow directions, and accomplish something independently. For teachers, this journey also brings the reward of seeing students develop essential math skills, such as fractions, measurement, addition, and multiplication. The hands-on experience with baking ingredients can even spark curiosity and lead to further exploration in areas like health or science. These are versatile lessons that will inspire both confidence and a deeper understanding of fractions.
My favourite cookie recipe
This cookie recipe is a favourite of mine because it can be made vegan very easily. Just substitute the milk for any plant-based milk and use vegan chocolate chip cookies. Any simple cookie recipe will work just as well for the lessons.
Dry ingredients:
- 2/3 cup quick oats
- 1 1/2 cup all-purpose flour
- 1/2 cup brown sugar
- 1/2 cup chocolate chips
- 1/2 tsp. ground cinnamon
- 1/4 tsp. kosher salt
- 1 tsp. vanilla extract
Wet ingredients:
- 1/4 cup olive oil
- 1/2 cup milk (any kind)
Steps:
- Pre-heat the oven to 350° Fahrenheit
- Add the dry ingredients together in a bowl and mix well.
- Combine the wet ingredients in a second bowl.
- Add the wet ingredients to the dry ingredients and combine.
- Scoop out tablespoon sized balls of cookie dough and place on a baking sheet.
- Bake cookies for 12 minutes or until golden brown on top. Make sure to give them time to cool before you move them from the baking sheet, as they can be fragile when warm.
- Enjoy your cookies!
Lesson 1: Measuring with fractions
In this lesson, students use cups and tablespoons to measure ingredients. Working in groups, each team will use a different measuring tool – such as a cup, ½ cup, 1/3 cup etc., and learn how to compare and add fractions to achieve the correct measurements. Students will learn how to choose the appropriate measuring tool to efficiently measure fractions of cups and tablespoons when baking.
How to pick the best measuring cups and spoons
Not all measuring cups are made equal for our purpose of investigating fractions. The ideal measuring cup should be transparent to let students see exactly how much is in the cup. A rectangular set of measuring cups and tablespoons may help students compare sizes easier than circular cups and tablespoons. You can even bring in a full cup with fractional lines on the side to show students how one whole cup looks compared to 1/2 cup or 1/3 cup in the same container.
Lesson 2: A double batch of cookies
In this lesson, students build on their fraction knowledge by learning to double, triple, and quadruple baking recipes. They will also determine how many batches of cookies can be baked with a limited supply of ingredients, reinforcing their understanding of adding and multiplying fractions.
Breaking down the whole number bias in fractions
You can connect this lesson to many other overall expectations in math. Students can see how multiplication is repeated addition by adding 1/3 cups together until they have one whole cup. Students may need help understanding how to add fractions together by adding the numerators but not the denominators of like–fractions (1/3 + 1/3 = 2/3, not 2/6). This misconception, known as the whole number bias, often arises when students encounter the rules for working with fractions, which differ from the rules for whole numbers.
Lesson 3: Baking our Favourite Recipes
In this lesson, students expand their knowledge of fractions by looking at recipes that they bring from home. Students develop skills to read and compare fractions and understand the relationship between fractions and ratios. They also practice adding and multiplying fractions of like and unlike denominators.
Students will learn about many kinds of recipes through this lesson, which has the potential for connections to be made between food and culture. From pierogi dough to Belgian waffle batter, challah to Montreal style bagels, and chebakia to kahk, baked goods connect us to families, holidays, and traditions passed down through generations. This leads to a culturally responsive fraction lesson that will engage all students and, who know, maybe even introduce them to their new favourite treat!
Author
Thomas Sayers
Student Teacher, Master of Arts in Child Study and Education Program (OISE/U of T)
