Mathematics
Grade 6
15 min
Complete addition and subtraction sentences with fractions
Complete addition and subtraction sentences with fractions
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Identify the missing fraction in an addition sentence.
Identify the missing fraction in a subtraction sentence.
Apply inverse operations to solve for unknown fractional values.
Convert between mixed numbers and improper fractions to facilitate calculations.
Find common denominators to add or subtract fractions.
Simplify fractional answers to their lowest terms.
Ever baked cookies and realized you only have part of the flour you need? 🍪 How do you figure out exactly how much more to get?
In this lesson, you'll learn how to find missing numbers in addition and subtraction problems involving fractions. This skill is crucial for solving everyday problems and understanding how parts combine or separate.
Real-World Applications
Adjusting recipes with...
2
Key Concepts & Vocabulary
TermDefinitionExample
FractionA number representing a part of a whole, written as $\frac{a}{b}$ where $a$ is the numerator and $b$ is the denominator.$\frac{3}{4}$ means 3 out of 4 equal parts.
Common DenominatorA shared multiple of the denominators of two or more fractions, necessary for adding or subtracting them.For $\frac{1}{2}$ and $\frac{1}{3}$, a common denominator is 6.
Equivalent FractionsFractions that represent the same value, even though they have different numerators and denominators.$\frac{1}{2}$ is equivalent to $\frac{2}{4}$ and $\frac{3}{6}$.
Mixed NumberA number consisting of a whole number and a proper fraction.$1\frac{1}{2}$
Improper FractionA fraction where the numerator is greater than or equal to the denominator.$\frac{3}{2}$
Inverse OperationsOperations that undo e...
3
Core Formulas
Adding/Subtracting Fractions
$\frac{a}{b} \pm \frac{c}{b} = \frac{a \pm c}{b}$
To add or subtract fractions, they must have a common denominator. Find the least common multiple (LCM) of the denominators, convert fractions to equivalent fractions with the LCM as the new denominator, then add or subtract the numerators.
Finding a Missing Addend
If $x + \text{fraction}_1 = \text{fraction}_2$, then $x = \text{fraction}_2 - \text{fraction}_1$.
To find a missing part in an addition sentence, subtract the known part from the total.
Finding a Missing Part in Subtraction
If $\text{fraction}_1 - x = \text{fraction}_2$, then $x = \text{fraction}_1 - \text{fraction}_2$. If $x - \text{fraction}_1 = \text{fraction}_2$, then $x = \text{fraction}_1 + \text{fraction}_2$.
To find the...
5 more steps in this tutorial
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Challenging
A recipe requires $4\frac{1}{2}$ cups of flour. You only have $1\frac{2}{3}$ cups. How many more cups of flour do you need?
A.3\frac{1}{6}
B.6\frac{1}{6}
C.2\frac{5}{6}
D.3\frac{1}{5}
Challenging
To solve $\text{?} - 1\frac{1}{4} = 2\frac{1}{2}$, a student incorrectly subtracts $1\frac{1}{4}$ from $2\frac{1}{2}$. What is the difference between the student's incorrect answer and the correct answer?
A.1\frac{1}{4}
B.2\frac{1}{2}
C.3\frac{3}{4}
D.5
Challenging
What fraction must go in the box to make this sentence true? $\frac{7}{8} - \square = \frac{1}{2} - \frac{1}{8}$
A.\frac{3}{8}
B.\frac{5}{8}
C.1
D.\frac{1}{2}
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