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## Arithmetic (all content)

### Course: Arithmetic (all content)>Unit 5

Lesson 17: Adding and subtracting fractions with unlike denominators word problems

# Adding fractions word problem: paint

Sal solves a word problem by adding mixed numbers with unlike denominators. Created by Sal Khan.

## Want to join the conversation?

• you are confusing me about splitting the bar graph
• Splitting the bar graph really isn't at all confusing.It means that you divide something into fractions so you can understand better.The best object to use is a bar graph.Sal divided the first two into different fractions.Then, when you converted the two into fractions with same denominators,you add them together.When you add it,you get the answer,which Sal demonstrated in the third bar graph. So it is not confusing at all.Thanks for reading this reply!
• nice assey
(1 vote)
• Okay so I'm not tryna be rude or anything like that, but I just have to say... what you said was pretty rude and also really unnecessary. Buuuuut for some unknown reason you posted it anyway so now I'm going to answer your mean questions:

First of all the videos are long because Sal has to teach things. I'd like to see you try and squish lots of stuff about subtracting fractions into a two-minute video. The videos are to help people learn, and sometimes that can take a while, but it's worth it to share knowledge.

Second: Sal doesn't teach shortcuts because they're kind of a lazy way to get through math questions. He teaches structured ways that can help you in many problems instead of just having you remember an algorithm. It's better to actually apply yourself than just remember a shortcut.

I hope you take what I said to heart because I really did spend a lot of time answering your questions when they really weren't very good questions at all and were quite petty and rude to Sal. In future, it would be appreciated if you please didn't use this chat page -- which is meant to ask people for help with math -- to complain. Thank you and enjoy your day.
• you are nice (:
• thank u for helping me i think ima get a 100
• question when looking for a common denominator
must it be the lowest you can find or can it be just any?
(1 vote)
• A common denominator cannot be "any" number, because it has to fit both fractions. However, it can be "any" fitting number. The reason you want it to be a smaller number is that it makes adding and simplifying easier. (see simplifying fractions) I hope this helped!
• This is the absolute worst example of how to do fractions. The shortest solution is
Step 1: to a get common denominator multiply the two bottom numbers together.
Step 2: Cross multiply the two ORIGINAL numbers to get 4/10 + 5/10
• guys thumbs up on this comment let's see the most thumbs ups I could get