Exploring Adding and Subtracting Rational Expressions

This video tutorial covers the process of adding and subtracting fractions with unlike bases. It begins with an introduction to the concept and the importance of finding the least common multiple (LCM) for denominators. The tutorial then outlines the steps for converting mixed numbers to improper fractions, finding the LCM, and performing the addition or subtraction. Several example problems are worked through to demonstrate the process, followed by application problems that show how these skills can be used in real-world scenarios.

What is the first step in adding fractions with unlike denominators?

• Simplify the fractions

• Find the least common multiple (LCM) of the denominators

• Add the numerators directly

• Convert mixed numbers to improper fractions

Tags

CCSS.7.NS.A.1C

What is the LCM of 4 and 6?

• 24

• 12

• 10

• 20

What is the LCM of 3 and 8?

• 16

• 24

• 12

• 8

How do you adjust the numerators after finding the LCM?

• Multiply them by the same factor as the denominator

• Leave them unchanged

• Multiply them by the LCM

• Add them together

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

After finding the LCM, what is the next step in adding fractions?

• Add the denominators

• Rewrite the fractions with the LCM as the new denominator

• Simplify the fractions

• Convert to mixed numbers

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

How do you convert a mixed number to an improper fraction?

• Divide the numerator by the denominator

• Add the whole number to the numerator

• Multiply the whole number by the numerator

• Multiply the whole number by the denominator and add the numerator

What is the result of subtracting 5/4 from 19/6 when the LCM is 12?

• -1 11/12

• 2 2/3

• -2 1/4

• 1 1/2

Tags

CCSS.7.NS.A.1C

How much lasagna was eaten if 4 2/5 pans were initially available and 1 1/2 pans were left?

• 3 pans

• 2 9/10 pans

• 3 1/5 pans

• 2 1/2 pans

Tags

CCSS.7.NS.A.1C

What is the result of adding 3 1/2, 2 1/3, and 5 3/4 miles?

• 11 7/12 miles

• 10 1/2 miles

• 11 1/4 miles

• 12 miles

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

What is the difference in height between a 3 3/4 feet tall rosebush and Emma who is 5 1/2 feet tall?

• 1 3/4 feet

• 2 1/4 feet

• 2 feet

• 1 1/2 feet

Tags

CCSS.7.NS.A.3