Finding Least Common Denominators and Multiples

This video tutorial explains how to find the least common denominator (LCD) of two fractions with different denominators. It introduces the concept of LCD as the least common multiple of the denominators and demonstrates how to find it by listing multiples. The video provides an example using the numbers 7 and 9, showing how to adjust fractions to have the same denominator and then add them. The tutorial concludes with an invitation for viewer feedback and suggestions.

What does LCD stand for in the context of fractions?

• Lowest Common Denominator

• Least Common Denominator

• Largest Common Denominator

• Last Common Denominator

Why is finding the LCD important when adding or subtracting fractions?

• It changes the numerators.

• It helps in multiplying fractions.

• It ensures fractions have the same denominator.

• It simplifies the fractions.

What is the least common denominator equivalent to?

• Greatest common factor

• Least common multiple

• Sum of denominators

• Difference of denominators

How can you find the least common multiple of two numbers?

• By subtracting the numbers

• By adding the numbers

• By dividing the numbers

• By listing their multiples

What is the least common multiple of 7 and 9?

• 72

• 56

• 49

• 63

What is the first step in converting fractions to have the same denominator?

• Subtract the numerators

• Add the numerators

• Multiply the denominators

• Find the least common denominator

How many times do you multiply 7 to get the least common denominator of 63?

• 10 times

• 7 times

• 9 times

• 8 times

What should you do to the numerator when you multiply the denominator by a number?

• Subtract the same number from the numerator

• Divide the numerator by the same number

• Add the same number to the numerator

• Multiply the numerator by the same number

What is the new numerator when 3/7 is converted to have a denominator of 63?

• 21

• 30

• 27

• 24

What is the new numerator when 4/9 is converted to have a denominator of 63?

• 24

• 26

• 30

• 28