Baking Math: Doubling and Halving

Double or halve a recipe with simple fraction math, swap cups for spoons when amounts get small, and plan for eggs, pans and bake times.

Sometimes you want twice as many cookies, or just half a batch. Changing the size of a recipe is called scaling, and it is math you can eat. In this lesson you will double and halve amounts with your grown-up.

You will learn

• How to double amounts
• How to halve cups and spoons
• How to halve eggs and choose a pan

What you need

• A recipe
• A pencil and paper
• Measuring cups and spoons
• Your grown-up

Steps

1. Double itTo double means to make twice as much. Multiply every amount by 2, or add it to itself. So 1/2 cup becomes 1 cup, and 3/4 cup becomes 1 1/2 cups.
2. Halve itTo halve means to make half as much. Divide every amount by 2. So 1 cup becomes 1/2 cup, and 1 teaspoon becomes 1/2 teaspoon.
3. Swap to spoonsSome halves have no cup of their own, so switch to spoons. 1/4 cup equals 4 tablespoons, so half of 1/4 cup is 2 tablespoons. 1 tablespoon equals 3 teaspoons, so half a tablespoon is 1 1/2 teaspoons.
4. Handle the eggsYou cannot crack half an egg. Wash your hands first, and check every ingredient with your grown-up for allergies, since some people are allergic to eggs. Then beat 1 egg with a fork in a small bowl and use half. To halve 3 eggs, use 1 whole egg plus half of a beaten one. Wash your hands again after touching raw egg, and no tasting the raw dough or batter.
5. Write it downWrite each new amount next to the old one, so you do not lose your place. Then check your math with your grown-up before you measure.
6. Think about the panKeep the oven temperature the same. A doubled cake batter goes into two pans, and a half batch needs a smaller pan. Bake times can change, so your grown-up checks early.

Try it

• 
  Junior Bakers

  Chocolate Chip Cookie

• 
  Junior Bakers

  Vanilla Cupcakes

Check yourself