Adding and Subtracting Fractions

This video tutorial explains how to add and subtract fractions with unlike denominators using the least common multiple (LCM). It covers the importance of having common denominators, finding equivalent fractions, and using LCM to rewrite fractions. The tutorial includes practice problems for both addition and subtraction, highlighting shortcuts and the concept of the least common denominator (LCD).

Why is it necessary to have common denominators when adding fractions?

• To make the fractions larger.

• To ensure the numerators are equal.

• To accurately combine the fractions.

• To simplify the fractions.

What is an equivalent fraction?

• A fraction with a different numerator.

• A fraction that is larger than the original.

• A fraction with a different denominator.

• A fraction that represents the same value.

How does the least common multiple help in adding fractions?

• It simplifies the fractions.

• It determines the new numerator.

• It identifies the common denominator.

• It converts fractions to decimals.

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

• Convert fractions to decimals.

• Add the numerators directly.

• List multiples of each denominator.

• Find the greatest common factor.

What should you do after finding the least common multiple?

• Rewrite the fractions with the LCM as the denominator.

• Convert the fractions to percentages.

• Add the numerators.

• Subtract the smaller fraction.

How do you adjust the numerators when rewriting fractions?

• Multiply by the factor used to change the denominator.

• Divide by the old denominator.

• Subtract the old numerator from the new denominator.

• Add the old numerator to the new denominator.

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

• Multiply the fractions.

• Add the numerators and simplify.

• Subtract the numerators.

• Add the denominators.

In the practice problem, what is the least common multiple of 10 and 2?

• 2

• 10

• 20

• 5

What is the shortcut when one denominator is a factor of the other?

• Only change the fraction with the smaller denominator.

• Change both fractions.

• Add the numerators directly.

• Multiply the fractions.

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

• Find the least common multiple.

• Multiply the fractions.

• Convert to decimals.

• Add the numerators.