How to Do Math In Your Head : Quick Math Tricks: Multiplying by 11

[therockstar1142]

Dude thnx alot

[jjclassjj]

This is a great video

[theqad123]

GOOD GOOD!

[eddieman47]

wow!! that's so cool

[mulherdoro]

me: Teacher, will you punish me for somthing I didn't do?

teacher: of course not!

me: I didnt do my homework

teacher: WHAT!?!!?

[Minionofonion]

WTH!!!!!



[MrVideojuggler98]

I feel smart now

[Shaymac48]

I like it



[SweetCandyPuff]

Thanks it helped me alot xxxx

[EpicSuccuss]

that is cool Never seen that before

[examinfo]

Why does the guy in the video look like he is being held hostage somewhere?

[TheVid3r]

mm nc lol im a 12 years old boy so that will be kinda helpful in my algebra :p

[OldSchoolSkill]

Though these tricks work, they do nothing to enlighten the viewer about WHY they work. There is no explanation.

The net result is the viewer gets a false impression that if he can just memorize some "trick" or gimmick for every set of multiplicands, he can conquer math.

It is far better to teach a single algorithm that works for ALL similar problems.

[MathTipsAndTricks4U]

if you like math tricks, check out my website dedicated to improve your mental math skills. its mathtipsandtricks. com

[smashcubie41]

0:01 for ads

[TomKaren1994]

See Ira Trachtenberg's book from 60+ years ago... all these "tricks" are in there.

[chirhocub]

Why do people treat math like it's magic? Do you understand why this works? I'll explain. Distribution of multiplication over addition. Your example 25 x 11 is the same as 25(10 + 1) = 250 + 25. We see easily why the two moves to hundreds place and the ones place stays the same. Additionally, it's now clear why the middle digit is the sum of the original two digits. Furthermore, any two digit number can be written 10a + b where a is between 1 and 9 and b is between 0 and 9. Then multiply

[babythebabyslings]

@chirhocub wow, thank you for this explanation. The video was helpful, but your explanation is what brought it home ;)

[davidgsr2k]

@chirhocub why do people treat card tricks like magic? because its new and exciting maybe? Not everyone knows the math tricks so it is magic to some..don't believe me, pull some of these at a bar, as dumb as it sounds it works and impresses

[maxie15o9]

I would just use the calculator ;) thumbs up!

[LoracUg]

hei, please thank u so much

[ParleLeVu]

It's actually easier just to multiply it by 10 and add then adding 1 times (x) on top.

11x11 = 110 + 11

11x56= 560+56

11x69=690+69

11x1550= 15500+1550

11x 22343546= 223435460 + 22343546

and so on.

[jaxxcorbin]

believe it or not that is how i started doing math naturally since childhood. no one taught me.

i am glad to know i was'nt wrong.

[TheRosangela1987]

Good, but howi is 21 x 35 using this method?

Thanks!

[romey87]

you a fucking moron. that takes way longer than doing it in your head. get a life. stop making videos. you're an idiot. shave your stache.

[jaxxcorbin]

@romey87 peace!

That actually is faster, it doest depend on how fast you can do the basic summation.

and apart from that it also depends on the logic you use to define diffrent number sets.

People who memories the multiplication tables might find it slow.

but people who perform a quick evaluation based on basic number logic will find it faster.

[littelG333]

@romey87 troll, i see you on other videos leaving a comment, go find something better to do loser

[chris8680]

whaaaaat that made everything way more convenient

[sabasabasaba77]

man, i can tell you easier way of that, take any number for example 57, so we have this 11 X 57 , now watch (10 X 57=570 we plus one more 0 to 57, and then we plus one more 57 to this number, 11 X 57 = 10 X 57 = 570 + 57 = 627

and on your way the sum of number mustn't be more than 9, if it will be it will fail!

for example try 67 or 37 or 55,

[gtq838]

expert village fails again

[unoriginality1]

@gtq838 lol true....true

[littlemsjing]

big help!!! thanks!!!!!

[Silver7Bird]

He would choose 69

[jhelen90]

old trick, but nice ^_^

[azy111]

how can put this value ansr 25*75

[niamarie7]

To  ilovemusiciBRASIL

ummm dude...

11 * 98

9_8

9+8 = 17 BUT you have the ten SO you + 1 to the 9 = 10 so

10 7 8

[ilovemusiciBRASIL]

try this 11x98 , u will get 1068 but in the alculator is 1078 , WTF is wrong??

[bharatnaruka]

@ilovemusiciBRASIL

not sure how you got 1068.

9+8 = 17, result will be 9+1 7 8 = 1078

[niamarie7]

ummm you carry the ten...9+8=17 SOO 9 becomes 10 then you put 7 in the middle...and have 8. 1078

[niamarie7]

ummm dude...

11 * 98

9_8

9+8 = 17 BUT you have the ten SO you + 1 to the 9 = 10 so

10 7 8

[theannoymous123]

tis piss me off

[Kameron02ify]

wow tht really helped me thnx dude

[COLDBUOY]

wow thats cool thanx man .........keep up the good work

[Caporacolo]

isn't just simplier to multiply the number by 10 and add the number itself? completely :p

[mrfardy91]

well that sucks because it only applies when using 11

[RETROBARBEii]

THANXX!

[MaSSiVe0101]

Daaamn... I do algyrythma or however you so spell that in english..

But I suck at doing math in my head.. Just never gets in their..

This will help a lot :)

fanx

[O0oXvXo0O]

Well you can beat the calculator or you can choose to use it. But this is fun for me. To figure out equations in my head. So i think this is fun and im learning myself to not use the calculator :).

[GothicaKenny]

LoL, from my eyes, all the time i search for fast calculation they use the 2 numbers 69 LOL too much sex?

[trpamhrh3]

@GothicaKenny I'd say too little :P

Isn't it easier to use that trick: 25

+25

----------  275

[cxiong116]

I feel dumb, Kool thinks dude. i never use my brain.

[xXKyrielleW43v3rXx]

use a caculator and its called take a penicl and paper and multiply my baby cuz can do tht oh and its called the break apart method.

[supergub1]

I can beat a calculator with that method, bigger dumbass.

[OldSmellyCrotch]

Here's a quick way of becoming a dumb-ass-- USE A CALCULATOR!!!

[xXKyrielleW43v3rXx]

Great I dea

[arnaud271]

fuck u

[lexcorona85]

As a kid in elementary, I found out to add.. Such as 25 on top of 25 offset such as you get 275 by having 5 + 0=5, 5+2=7, and 2+0 equals 2.....the same thing shown here. This is not easier than 25x10+25=225.

[gutozao]

Duh, no wonder you don't get it.

In no way, shape or form is 25 x 10 + 25 = 225. Think!!

Man, some people are bound to live with a calculator for the rest of their lives.

[lexcorona85]

Yes, thank you for pointing out my type O. It's a passing comment, but what I meant was 25*10+25= 275. Some people do live with calculators for the rest of their lives. They are some are the brightest people who live. Engineers use calculator everyday.

[heart4evilyn]

koool thanks

[mrsthursday]

Ashwinder. Nobody's going to mistake you for a brain.lol.

[hsalsi]

nah...i prefer the 10*25+25...much easier .

[Nherwyziant]

Nah, i prefer his (or her hehe) idea. But yours is also a smart way but i just don't like it :)

[jaxxcorbin]

@hsalsi not bad

[JustCallMeZachG]

cool, once you get this triple to six digits just are the same basically

[Physicsandmaths]

In my opinion tricks like these are quite useless, especially if you don't understand why they work.

If you want to multiply by 11, an easier way to understand it would be to do ten times the number, and then add the number once more so you've got 11 times the number. So for example,

11x25 = 10x25 + 25 = 250 + 25 = 275

[MetalHeart8787]

physics - isnt that also a Trick?

what about 78x25 ? you need to think of another way. Yes understanding is important But when you have a Test or need to do it quik it Helps.

[mdiem]

It's the same thing - though it is important to understand why the trick works, i.e. where it comes from.

[jechchatt1995]

thank u it helpt me a bit

[hectorandrespv]

hey its math , not supposed to make you laugh !

[sonicboy678]

You'd be amazed at my agreement with you. I actually agree with you.

[nickolayer]

So do I.

Just in case anyone wonders, I support devouroringone's method. Write a zero at the end, add the number itself and that's it.

[simpsonsfan753]

Glad2teach have a better way to do it . look at his videos . like 1453 * 11

first take the first number 1

then take the first number and plus it with the next .

just keep doing that and in the end you get this number 15983. that easy :D

[Rami1997]

Funny and easy way to do it ......

[rocknrolllyrics]

i learnd this trick in 2nd grade!! My brother was in middle school at the time and I found the "11" trick in his math text book....

[zmk10101]

it's amazing how math becomes so interesting when its instructor looks like brad pitt

[devouroringone]

i find it easier to multiply the number by 10 and add the number itself later

[Jerome27021981]

How does this work with numbers larger than 99?

For instance, 231 x 11

[luvablebetty]

this is simple and useful

[mike300zx1108]

this is a stupid confusing way to multiply by 11. its a lot easier to add a zero at the end and add the original number to it.

[Idmaif]

so how do you do stuff like 11x430 or 11x1034?

[DarkOreK]

esay 1034 x 11

we keep the first number as it is = 1

the second 1+0 = 1

the third 0+3 = 3

the next 3+4=7

and the last we keep as it is = 4

now let's put them together

11374

[RexNunc]

This guy is over the top with enthusiasm!

[kenspin]

This one's rather simple. I figured this out on my own, but good to know I was on the right track!

[DrLsw]

!! i found out about it on my own last year to! i got bored in math so i tried to find a pattern in 2,3, and 4 digit numbers multiplied by 11

[andsusul]

I know this!

Its actually quite simple. Ive been doing this type of multiplication on my head since I was atleast five years old.

Its all just about adding.

You make it seem more complicated than it really is.

Just take the first number

411213= 4 (the first number)52334 3(three being the last number)

Its super simple.

[pzuffi]

lol 69