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### Course: MAP Recommended Practice>Unit 34

Lesson 13: Strategies for adding and subtracting fractions with unlike denominators

# Visually subtracting fractions: 3/4-5/8

Learn about understanding how to add and subtract fractions with unlike denominators. Practice finding a common denominator, and demonstrates how to visually represent these operations.

## Want to join the conversation?

• Is there a quicker way to do the math? For subtracting fractions; Like in your head for when your at the store or something. Please teach me if there is so I know how to like, that! Thanks!
• Find the common denominator,in this case,8.Then multiply 4 and 2 and you get 8.Do the same with the numerator and you get 6. 6/8 -5/8 is 1/8.Hope this helped.
• is 193 a prime number?
• Yes, 193 is a prime number because 193 only can be divisible by 1 and itself. A prime number means it only can be divisible by 1 and itself.
• So then how would you do 3/4-2/3, were the denominators can't go into each other?
• I keep studying how to subtract fractions, but it's so hard.AARRGGHH!
Can you plz help me?PLZZZZZZZ!
Thanks!
• I’ll show you an example: 2/3 – 2/5 = ?
First you find the least common denominator of 3 and 5 which is fifteen because 3 x 5 = 15 and 5 x 3 = 15. Secondly, you are going to do the same to the numerators: 2 x 5 = 10 and 2 x 3 = 6. You put the 10 in the numerator of 10/15 and put the 6 in the 6/15, then you simply subtract the numerators. 10 – 6 = 4. Then the answer would be 4/15. Hope this helps!
• how do you set up fractions on here now.
• but how do you reduce the fraction?
• To reduce a fraction, divide the numerator and the denominator by the GCF.

(1.) 8/12 (4 is the GCF of 8 and 12, so we will divide by that number.)
(2.) 2/3
• why im so comfusseed is this faster.
• You can go into settings and slow down the video if needed.
• actually a prime number is a number that can not be divided by any number besides itself and 1.