Common Denominators

Front

What is a common denominator?

Back

A common denominator is a number that is a multiple of the denominators of two or more fractions. It allows fractions to be compared or added together.

Front

How do you find the least common denominator (LCD)?

Back

To find the least common denominator, list the multiples of each denominator and find the smallest multiple that appears in both lists.

Front

Find the common denominator for 3/10 and 4/7.

Back

70

Front

What is the common denominator for 3/4 and 5/6?

Back

12

Front

Find the common denominator for 2/7 and 3/5.

Back

35

Front

What is the common denominator for 2/5 and 3/8?

Back

40

Front

What is the common denominator for 4/9 and 5/12?

Back

36

Front

Why is it important to find a common denominator?

Back

Finding a common denominator is important for adding, subtracting, or comparing fractions.

Front

What is the least common multiple (LCM)?

Back

The least common multiple is the smallest multiple that two or more numbers share.

Front

How can you use prime factorization to find the LCM?

Back

To find the LCM using prime factorization, break each number down into its prime factors, then take the highest power of each prime factor.