Mathematics
Grade 6
15 min
Add and subtract fractions in recipes
Add and subtract fractions in recipes
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Identify fractions and mixed numbers in recipe contexts.
Find a common denominator for two or more fractions.
Add and subtract fractions with like denominators.
Add and subtract fractions with unlike denominators by finding equivalent fractions.
Convert between mixed numbers and improper fractions to solve recipe problems.
Simplify fraction answers to their lowest terms.
Apply fraction addition and subtraction to scale or adjust recipe ingredients.
Ever wondered how much flour you'd need if you wanted to double a cookie recipe? 🍪 Or how much milk is left if you use some for pancakes? 🤔
In this lesson, you'll learn how to add and subtract fractions, especially when you're cooking or baking! Understanding fractions is super important in...
2
Key Concepts & Vocabulary
TermDefinitionExample
FractionA number that represents a part of a whole. It is written as a numerator (top number) over a denominator (bottom number).In a recipe, if you use 1/2 cup of sugar, 1/2 is a fraction representing half of a whole cup.
NumeratorThe top number in a fraction, which tells you how many parts of the whole you have.In the fraction 3/4 cup of milk, '3' is the numerator, meaning you have 3 out of 4 equal parts of a cup.
DenominatorThe bottom number in a fraction, which tells you how many equal parts the whole is divided into.In the fraction 3/4 cup of milk, '4' is the denominator, meaning the cup is divided into 4 equal parts.
Common DenominatorA shared denominator for two or more fractions. It's necessary to find one before adding or subtracting...
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Core Formulas
Adding Fractions with Common Denominators
$ rac{a}{c} + rac{b}{c} = rac{a+b}{c}$
When fractions have the same denominator, simply add the numerators and keep the denominator the same. Remember to simplify your answer if possible.
Subtracting Fractions with Common Denominators
$ rac{a}{c} - rac{b}{c} = rac{a-b}{c}$
When fractions have the same denominator, simply subtract the numerators and keep the denominator the same. Simplify your answer if possible.
Adding/Subtracting Fractions with Different Denominators
To add or subtract fractions with different denominators, first find a common denominator (often the Least Common Denominator, LCD). Convert each fraction to an equivalent fraction with the common denominator, then add or subtract the numerators.
Use this ru...
4 more steps in this tutorial
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Challenging
You start with a 5 1/2 cup bag of flour. For a pizza dough recipe, you use 3 1/3 cups of flour. Then, you add 1/4 cup back to the bag because you took too much. How much flour is in the bag now?
A.2 1/12 cups
B.2 1/4 cups
C.2 5/12 cups
D.2 7/12 cups
Challenging
A recipe for a large pot of chili calls for 4 1/2 teaspoons of chili powder. You want to adjust the recipe to make it less spicy, so you decide to use 1 3/4 teaspoons less. How much chili powder should you use?
A.2 3/4 teaspoons
B.3 1/4 teaspoons
C.2 1/2 teaspoons
D.3 1/2 teaspoons
Challenging
You are making a punch that requires 2 1/3 cups of pineapple juice, 1 1/2 cups of cranberry juice, and 3/4 cup of ginger ale. If the punch bowl holds 5 cups, how much space is left in the bowl after adding all the ingredients?
A.1/2 cup
B.4 7/12 cups
C.1 cup
D.5/12 cup
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