answersLogoWhite

0

One way to compare fractions is with common denominators. The process is the same as finding the LCM of integers.

Example: 1/30 and 1/42

Factor them.

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Combine the factors, eliminating duplicates.

2 x 3 x 5 x 7 = 210

1/30 = 7/210

1/42 = 5/210

1/30 > 1/42

User Avatar

Wiki User

10y ago

Still curious? Ask our experts.

Chat with our AI personalities

JudyJudy
Simplicity is my specialty.
Chat with Judy
MaxineMaxine
I respect you enough to keep it real.
Chat with Maxine
BeauBeau
You're doing better than you think!
Chat with Beau
More answers

Example: 1/30 and 1/42
The LCM (LCD) of 30 and 42 is 210.
30 x 7 = 210, so multiply the fraction by 7/7.
1/30 = 7/210
42 x 5 = 210, so multiply the fraction by 5/5
1/45 = 5/210

User Avatar

Wiki User

12y ago
User Avatar

After finding the LCM use it as the denominator.

Multiply by what would change the denominator to the LCM.

Like 1/4 and 1/18

The least common multiple of 4 and 18 is 36.

4x9=36

18x2=36

User Avatar

Wiki User

10y ago
User Avatar

Example: 2/3 and 3/4

To find the least common denominator it is necessary to find the least common multiple of 3 and 4, which is 12.

2/3 = 8/12

3/4 = 9/12

2/3 + 3/4 = 17/12 = 1 and 5/12

User Avatar

Wiki User

8y ago
User Avatar

When adding and subtracting unlike fractions, find the LCM of the denominators and convert them to it. In this case, it's called the least common denominator, but it's the same process.

User Avatar

Wiki User

8y ago
User Avatar

Add your answer:

Earn +20 pts
Q: How is the least common multiple used when adding and subtracting fractions?
Write your answer...
Submit
Still have questions?
magnify glass
imp