Why borrowing works

[ChuckTheDuckNorris]

I am taking algebra 2 honors, but there is something that just fascinates me about some of your videos on simple math. It gives me a way of thinking I never knew about! Thank you!

[Triathletep]

would there be a particular field in math that borrowing belongs to?

[theantiantichrist]

Oh. I spent this entire video thinking; 'What has this got to do with the economical practicality of lending?'

I've never heard this referred to as borrowing. It's just the natural way to add and subtract large number

[INMATE2468]

3:37. Top left corner is flying spaghetti monster, Ramen!!!!

[blessed323]

Thank you!!! My son missed a week due to pneumonia/asthma and I was having a hard time getting this across to him. This really helped him understand how and why!

[CasuallyCora]

some of the things you teach in your videos are sometimes alittle more than what im learning in class (8th grade) but you always get right to the point in the end. these videos are GREAT. and they help people A LOT. thank you!

[charles47254]

Wow this is grate



[JoshBxD]

wow fascinating

[Chris242tt]

BORING!!!!no offence!

[dtrip09]

@ifginc what does this have to do with this leson lol

[HelpWithMath1]

Learn exactly why borrowing works in under ten minutes. How cool is that?

I shudder to think how many kids miss this in class. So here it is.

BTW, does anybody know which clever soul first came up with this way of doing subtraction?

[sleeper2345]

@HelpWithMath1 I believe it is credited to William Brownell. However, this is not the most efficient algorithm for subtraction. Many different subtraction algorithms are taught in various countries around the world.

[odinncool]

This was extremely useful! I learned how to do that a few years ago and I did like you said! I didn't know why I was supposed to do this and that and eventually forgot!

thank you!

[FarrenfollowsBen]

lol borrowing was always so mystical

[johnfm1061]

this is nice, but in my method of subtraction you would look at the 5 and 6 and simply add the difference from 6 and 10. That would make the number a 9. This action would reduce the entire number to 99. Thus making the final answer simple to figure out. 1005 - 616 Difference from 10 = 4. add to 5= 9 100 natural reduction of remaining number = 99. 99 5

-61 6 38 9

final answer 389

[mickeymouselover1998]

=) ur good!

[musicmomof11]

I prefer to call it "regrouping", instead of "borrowing"........you don't give it back! LOL

[ThatIsNotDeadWhich]

And that differs from the way "borrowing" is used in the current financial situation in what way, again? ;-P

[zimcode3]

Sure you do! what do you think happens when you finish the problem and move on to the next? or even erase the problem. It goes into a whole nother demention of just MATH and thats when it gives the numbers back that it borrowed! (Hope that explains it!)

[ugerWadi]

@musicmomof11 100% agreed. Borrowing should be called regrouping...

[LordAlda]

Nice, I do it differently now then I did before.

5000-332 for example, I would think of the value that would occur occur 332 less than 5000 from left to right. 5k to 4k, 000 to 4700, then 4700 to 4670, and lastly 4670 to 4668.

It maybe hard to understand, but it's something like a rapid countdown of numbers.

[infidelguy]

This is cool. So it can also be: 470+30+12 too! You take whatever you want out of the 500 as long as it's greater than or equal 30 in the tens place. So, the top number could be: 460+ 40 + 12 as well. Awesome.

[xodarap]

this is a great demo! Many thanks to Mr Khan!

when I was a kid they taught us to [for eg:

in 512-38] "8 from 2 you can't, borrow 10 makes 12. 8 from 12 is 4 - write that down; pay back 10 so cross out the 3 & write 4. 4 from one you can't so borrow 10 makes 11. 4 from 11 is 7 - write that down; pay back 10 so write 1 under the 5. 1 from 5 is 4 - write that down. Ans: 474

that was in Wales where they had "other ways" of doing lots of things!

Cheers :-)

[LordAlda]

That's cool, never heard of it done that way.

[ShadowKillerJ]

perfectly done!! thanks! great site too!

[markjsimeon]

Great stuff! One suggestion: always use the appropriate number of digits for each place column. So, to expand 1005, you would write it out as 1000 + 000 + 00 + 5 (not 1000 + 0 + 0 + 5). Aight?

[eliphant0723]

@paulg53

Actually, 'it' was never taken :)

[wooperman3000]

THANK YOO THANK YOO

[paulg53]

I don't understand why it is called borrowing. It's not borrowing: you never give it back.

[Ormaaj]

I think the right side is how most people subtract in their heads anyway. i didn't even think of doing it in the left way. Though really they are completely equivalent.

[thekingofoakland]

thanks bro

[realistic001]

Wow, this makes perfect sense! And to think I did not understand the process of borrowing all these years!!! Thank you.

[JackiexAndxGeorge]

Many thanks broseph, been out of education for a few years and going back to college in September, and you sir, are my hero.

Helps me remember some stuff I would otherwise have forgotten and fall behind.

[kleesin]

All thse math instructional videos are WHY I will be able to go back to university. I learn so well from visual/audial ... but not so well from books. Thank you, thank you, thank you!

[RedSeaCoral]

not only was it useful but also brilliantly educating. thank you very much for taking the time and effort to post this video.

im sure many young and slightly older studens will aprichiate this video. thank you once again ;)

[ghalbeafg]

thank you so much. we appreciate u taking your time to do this for us

[benoc1402]

you are a sick teacher...thanks alot.

[zackoman123]

u stupid people didnt know how it worked lol

[mrgatorland]

wow, I'm an engineer and that didn't even cross my mind, lol. Thank you.

[LittleVato33]

Awesome,he doesnt rush,he doesnt use big words,he explains every step,he does variuos problems,and...i subscribed....

[gnabizz1]

Thank you! that was awesome, I am in College and our professor asked us how does borrowing work? I was surprised to know, as many other found, we had no idea. :)

[andrewedwardjudd]

You are truelly doing great work here! When i think back to the pain i had learning i can see how learning can be fun:-)

[hedikomoon]

Thank you sooo much!

[lamont152]

Thanks you so much. I always wanted to know why borrowing works. Now I see. Thanks again and all of your videos are awesome.

[coolieo389]

I never knew why borrowing work. Thanks for the video it was very informative.

[vickiormindyb]

I like your 'short way' better than the one I was taught--she told me to go backward one number on the integer line and add 10 to it. I'd always forget because I see no numbers that exist in lines or rows.

I was in a severe accident, and comatose for 5 days. After I woke up I had to relearn all my math, beginning at a 2nd grade level.

The left side of my brain sustained the most damage, so I have to watch the videos more than once, but I like that you believe I'm still capable of learning.

[Krissam2k]

that's the spirit man, keep up fighting, it ofcourse saddens me you were injured, but it's really nice to see someone trying to learn math, as opposed to the attitude i often see at school. "i dont get, this this sucks, why do i have to learn this?"

[emorgamz]

very creative

[darkwspyder]

Thanks. This is so interesting. I actually like it the long way because like you said, you'll remember it and its more comprehension to it. I wish teachers didn't teach just for tests.

[ultramanxk7]

Hummm, that's a good point.

[anvilsalesman]

nice - way too many people know the methods but not why they exist.