Adding and Subtracting Fractions and Mixed Numbers
Grade 8 math lesson on adding and subtracting fractions and mixed numbers with like and unlike denominators. Students learn to find common denominators, add and subtract numerators, convert improper fractions to mixed numbers, and simplify results.
Key Concepts
New Concept This course builds a complete understanding of arithmetic, from fundamental operations to complex problem solving with fractions, decimals, and percents. What’s next This card introduces the big picture. Next, we’ll dive into a key skill: adding and subtracting fractions through worked examples and visual models.
Common Questions
How do you add fractions with different denominators?
Find the least common denominator (LCD) of both fractions. Convert each fraction to an equivalent fraction with that denominator, then add the numerators. Finally, simplify the result.
How do you add mixed numbers?
Add the whole number parts and the fraction parts separately. If the fraction parts sum to more than 1, convert the excess to a whole number and add it to the whole number sum.
How do you subtract fractions with unlike denominators?
Find a common denominator, convert both fractions, then subtract the numerators. Sometimes you need to borrow from the whole number part if the fraction being subtracted is larger.
What is borrowing when subtracting mixed numbers?
When the fraction in a mixed number is too small to subtract from, borrow 1 from the whole number and convert it to a fraction. Add this to the existing fraction before subtracting.