Fractions & Proportions : How to Cross Multiply Proportions

Cross multiplying proportions is a straightforward process that is the same as cross multiplying fractions. Cross multiply by multiplying a numerator by the other side's denominator with help from a math teacher in this free video on proportions in math.

Expert: Jimmy Chang
Bio: Jimmy Chang has been a math teacher at St. Pete College for nearly a decade. He has a master's degree in math, and his specialties include calculus, algebra, liberal arts, math and trigonometry.
Filmmaker: Christopher Rokosz

[skillybiskuit]

I’m 21 and I just barely graduated at 18. I might as well had crawled across the stage, and it took a lot of virtual classes and cheating to get there. After a 3 year break and some maturing, ive suddenly acquired a will to learn math again. My problem was going straight to algebra when there’s a few foundation math topics I never solidified. I’m now interested in going into the science field, which obviously required an extensive amount of math knowledge, and these videos are a huge help. Thankyou for creating this, and anybody whose reading, it doesn’t matter how bad you think you are you can do it too. But it takes your own free will to want it, not any outside pressures forcing you. Good luck to anyone who needed to search this video up.

[GPSGO]

Thank you -- here I am a 48 year old man having to dive in & help my 12 yr old son with this crap I havent seen in 30 plus years!!! Gawd! -- Thanks! 

[ahbm]

I was so stuck on my (10th grade) homework and my teacher doesn’t teach. Thank you!!!

[christopherkelly]

Thank you for taking the time to make this video. Reviewing / re-learning math right now and clear concise videos like this are very helpful.

[dustinnelson]

Hey man, I just wanted to say how much I love your videos. I'm a reporter and they've been a lifesaver in checking my work on data. Math has never been my strong suit and people who think they'll never have to do it again after high school are wrong. I know I was.

[Ashley_Mariee]

i've been trying to understand this for about literally 3 years in math classes, and you've made me learn this in 2 minutes. wowowow thank you!!

[citlaly]

This video really helped because I had trouble doing my homework 👏👏👏👏

[chiibioobrii]

I feel embarrassed that I have to look this up but its been about 15 years since I had to cross multiple anything.

[elliari]

This actually help so much? This video literally help me for only 2 minutes, while my teacher has to spend a whole week teaching this lol (note: even though my teacher has been teaching this for a week, I literally have no idea of what she was talking about)

[meaganfearing]

Great video - quick and easy. Needed to use this to figure out income due to a reduction in hours. We knew the hours, but not the project gross income (not an hourly wage). Couldn't remember when to multiple and when to divide. Thanks again!!!

[CrescendoCrimson]

I have been trying to explain this to my mother for the last 30 minutes, but she didn't understand until I pulled this up. Thank you so much for saving me the frustration.

[hiddendevs]

Wow, last year my grade was high B's this year it is going from high 60's to low 70's and back to high 60's.This was very helpful for the first time in 2 years I finally understand a mathematical strategy!
One thing my math teacher did have to say when he was teaching all the strategy's for proportions, you have to be careful when cross multiplying, because it takes longer than doing a one step equation.

[shroom]

COLLEGE?
I'm here (8th grade) because I forgot how do it- I learned how to when I was in 6th-7th

[camronjones]

this dude teaches this to make it so easy to understand great job jimmy!!!

[johnjack]

Thanks jimmy your a life saver I have a test tomorrow and because of you I’ll think I’ll pass it

[michaelbrocaglia]

God bless Google for creating YouTube and influencing Jimmy to post this! I have never understood math in general and this man has helped!

[theora]

Thank you so much this was better teaching than my math teacher did

[Atlasboatdocks]

Thank you for explaining. My 7th grader came to me for help, could answer the question, but to show the work was aggravating. Helped a lot

[wolfgangmaddoxbauer]

Could you make a video on how to cross multiply with 3 fractions? Great videos keep it up!

[Maashu-Baandeddo]

thank you so much I forgot to bring home my math notebook and found this on youtube! very helpful