Setting up proportions to solve word problems | 7th grade | Khan Academy

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Some examples of writing two ratios and setting them equal to each other to solve proportion word problems

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Grade 7th on Khan Academy: 7th grade takes much of what you learned in 6th grade to an entirely new level. In particular, you'll now learn to do everything with negative numbers (we're talking everything--adding, subtracting, multiplying, dividing, fractions, decimals... everything!). You'll also take your algebraic skills to new heights by tackling two-step equations. 7th grade is also when you start thinking about probability (which is super important for realizing that casinos and lotteries are really just ways of taking money away from people who don't know probability) and dig deeper into the world of data and statistics. Onward! (Content was selected for this grade level based on a typical curriculum in the United States.)

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[Vector_Ze]

I'm an old guy who hasn't been in a classroom in 35 years.  Mathematically, I went through college Calculus level 1.  But, it surely should go without saying, I've forgotten much through lack of use over the decades.  A few years ago, I bought a "Calculus for Dummies" book.  And the refresher was great!

Instruction has changed a lot since I was in school.  At each grade level it is clear that subjects being taught now are much more advanced than what I encountered at the same levels.  And a lot of procedures are different too.

For my own gratification, I started doing the course on the Kahn Academy web site 4-5 days ago, starting at 3rd grade level math and working up.  I'm now at 7th grade.  Proportions don't bother me, but word question have always seemed to unnecessarily complicate things. It's hard to fight the desire to just solve for the variable.

The videos do a good job of filling in the void of not having an instructor to question when something is unclear.  So, thanks.

[nawh]

Love the teacher's voice! So soothing for us suffering from math anxiety!

[markloves]

Ty was always clueless of which way to write it...rlly helped ❤️

[leighg]

Khan, you have helped so many people to work through the beauty of math...thank you... I am an elementary and middle school principal.

[mrman]

it  is very clear for me you explain it very well

[repwarrior]

Its weird how these vids are helping me more then my math teacher

[domnatmusk]

I have the Starr test in 10 minutes and this helped me a lot 😄

[stephsavvy]

needed this refresher before the TEAS. so simple and made easy to understand!

[sardarbaig]

This is the BEST it helps much THANKS :)

[jdpoohmac]

5:27 "lemme do that in that blue color"

[kimjohnson]

You are a really great help. Thank you for teaching me how to do the math right.

[thevessel]

I can't believe that I HAD to watch this video on MY time outside of school

[AEL]

What were the answers? I want to make sure I was correct

[epicvideos]

this is Joshua Earle this video helps a lot

[elim.]

i was studying for my test it said the test was gonna be about solving word problems proportionally...i had no clue what to study for till i saw this video.

[Sundropicee]

Thank you You help meh with a quize I have trmorrow 🙂

[save_potato]

I'm ten years late, but at least my homework is done

[HealingNations]

This video was very helpful. Thanks so much!!!

[Qiqi]

thx but I still don"t know how Im supposed to figure out this problem: The distance a car travels is proportional to how many rotations its wheels make. A certain car travels 245 feet in 30 rotations of its wheels. How far will the car travel in 50 rotations? The d be equal to that distance. Set up and solve a proportion for the value of d. Round to the nearest tenth.
I HAVE A QUIZ TOMORROW HELP

[yaoiisnotexplicit]

So on number one, can you switch only one side and it can still be right?