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Stop for a minute and reflect on your definition of real-world math. Often, we think of real-world math as word problems that use a real-life situation as the context. My only problem with that definition is that in the real world, math is often messy. Consider, for example, word problems about scaling recipes up or down. Scaling up, for example doubling a recipe, poses no real problem. That is, since you’re multiplying, the numbers will always work. Scaling down, however, involves division and typically the numbers used in these problems are carefully chosen so they can neatly be divided. But is that what actually happens in the real world? Absolutely not.

### Cooking for one

When you are cooking for one, you are scaling down a recipe that is typically written for 2, 4, or more servings. Trust me, the quantities don’t always divide easily. Often, you have to make decisions about how much of the ingredients to use to keep the recipe in balance.

Here’s an example. I found a tasty recipe for Chicken Cordon Bleu. It’s kind of a fancy, stuffed chicken dish.

Here is the ingredient list, which is for four servings:

• 4 skinless, boneless chicken breast halves
• 1/4 teaspoon salt
• 1/8 teaspoon ground black pepper
• 6 slices Swiss cheese
• 4 slices cooked ham
• 1/2 cup seasoned bread crumbs

Think about how you would scale this recipe for one serving. Give it a try!

As I start to scale it down to one serving, some of the ingredients are straightforward. I will need one chicken breast and 1 slice of cooked ham. Even the Swiss cheese is a simple division problem–6 divided by 4 = 1.5, so I need 1 1/2 slices of cheese. Let’s tackle the bread crumbs next. I can do the division. One-half divided by 4 is 1/8. The problem is that my measuring cup set doesn’t have a 1/8 cup. So now I have to truly problem solve. My smallest measuring cup is 1/4 cup. How will I use that cup to measure out 1/8 cup of bread crumbs? Finally, there is the salt and pepper. When I do that division, I get 1/16 teaspoon of salt and 1/32 teaspoon of black pepper. How will I measure that, since my measuring spoons certainly don’t come in sizes that small? Here’s something I notice. The recipe calls for twice as much salt as pepper. If I want to keep the recipe balanced, I should keep that ratio. My smallest measuring spoon is 1/4 teaspoon. For the salt, I need to fill that spoon 1/4 full. That’s not much salt. And I need even less pepper.

Wondering about the best way to practice this skill? Actually cooking, of course! Find a recipe that sounds good, scale it down, and cook it! The conversations you’ll have with your child while preparing the recipe will provide great insight into your child’s number sense and true problem-solving abilities.

If you try this at home, I hope you’ll share your experiences in the comments or on Twitter!