How to Do Math In Your Head : Quick Math Tricks: Using 2 to Simplify

[jwm239]

...I noted that 67 x 3 is 201, which is very easy to multiply by any 2-digit number...and 3 is a factor of 48, thus: 48 x 67 = (67 x 3) x (48 / 3) = 201 x 16 = 3216.

[RUL1S88]

1:11 - PWNED!

[Mrniks89]

wrong calculation during 4th step

268*2 = 536 and not 538

[Mrniks89]

wrong calculation during 4th step

268*2 = 536 and not 538

[precious21ism]

You might as well just did it the regular way since you had 2 do all of that

[Jazzie646]

Well, at least when we put it like that we're showing our work. Well done!

[srang1984]

Following what you presented, we do need something to note: cannot use only head as you mentioned at the beginning of the clip. Conclusion: Multiply using classic method is the best.

[SuperChunky420]

bakwassssssssssss



[JonasFromNarvik]

The easier way is to round 48 to 50, then to multiplie it with 67 you divide 67 by 2 and get 33,5. Then you add 2 zeros. (3350) then you subtract the difference from 48-50(2) times 67. So you'll end up with: 3350-(67x2)=3350-134=3216!

[JonasFromNarvik]

The easier way is ti round 48 to 50, then to multiplie it with 67 you divide 67 by 2 and get 33,5. Then you add 2 zeros. (3350) then you subtract the difference from 48-50(2) times 67. So you'll end up with: 3350-(67x2)=3350-134=3216!

[ukko82]

and what if i want multiply for egz 43x67 huh?

[BobByler]

"Vedic Math Calculator" Try any number and find tricks to solve it @ maths.kuchnaya.com

[noxure]

Takes too many steps.

If you do it like this:

50*67= (6700 / 2) = 3350

2*67= 134

3350 - 134 = 3216

It requires less calculations.

[daushnz]

@noxure luls make a vid

[ofakar]

@noxure yeah.. or if the numbers aren't close to an easy number like 50, you could use his method to get to a number close to an easy number and use your method

[puringnoobs]

@noxure Do something like that

50*67=?

5*6=30 5*7=35 delete that zero and write 335. Then multiply it by 10 coz its 50 not 5. xD

another one :

30*46=?

3*4=12 3*6=18 then youll get 1218. do this : 1(2+1)8 = 138 and + 0 its 1380

[JosephBlessYou]

Come on u sucks man.

[ironkatia]

still doesn't make any sence.

[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.

[nobodyiixgr]

@romey87 are you a troll or what?i bet you can't do this in your head,so that's why you are trolling this video.Moron.

[laurentziu97]

1:06 -> 268x2 = 538 ?

[swdsverige]

@laurentziu97 . yup expervillage is wrong!!!!

[AbeLeBabe]

@swdsverige you're stupid-er.

[AbeLeBabe]

@laurentziu97 its 536-.-

2 times 8 is 16, not 18 smarts.

[DrakoV3]

Id rather Multiply 4 x 6 for 2400, 8 x 6 for 480, 4 x 7 for 280 and 8 x 7 for 56, add them all and you get 3216, but i cant do this in my head...

[xnubiax]

just use a calculator..

[littelG333]

@xnubiax Well I have to take a double digit teest without a calculator, you cant always rely on a calculator to help you, might as well learn this tricks even though it takes practice.

[LilKempy]

@littelG333 - well as long as your double digit test didn't require mental math...you should've done just fine by writing it out.

[her2death]

really i think it would be a lot easier to just multiply where as this way you have to take forever to find out what you need to divide by and how many times to get the number so this way is wayyy longer to me

[MistyGirl3000]

thxs! i roised from a D to a A!!

[QwertyNiji]

@MistyGirl3000 good like rising from an F to a D in English.

[Tobey7049]

So you rely on the cashiers to calculate for you because you are too dependable on your TI-89. That is so sad! Just use you demag once in a while and you will be fine! Besides most Universities do not allow calculators during finals.

[Rachel2000000]

o_____O ouch..... i rather do working thank you anyway

[moscovman232]

in other words, find the factors of one of the numbers, then multiply the other number by those factors.

[onthecuttingedge2005]

there is and easier and faster way.

[husthisshet]

mommy!!

[zemzamiimad]

268*2 is 536

[tissa71]

it is A LOT easier to just do it on a piece of paper than try to come up with all those numbers u came up with

[altha2008]

@tissa71 a lot easier is to use a caculator

[tyhughamster]

O___O my head hurts so bad right now rofl

[munirah1993]

by the time you finish that,the exam will be over...that's what my maths teacher said,'do not take too long on 1 question.'

[siddharthnng]

by the time u finish with this problem.... ill be done with my noobass calculator

[freckzne]

I suggest you not to stand in sun otherwise your head may catch fire...bhoosa bhara h sale ke dimag me..

[siddharthnng]

bhoosa tere baap ke sir mein hoga saale, when you sit in finals for calc 2 no one is gonna do this shit in head, everyone uses TI 89's. I'm not criticizing the technique this guy is using but its just not worth it..

[Tobey7049]

@siddharthnng You can't rely on calculators all the time. Sometimes you do use your demag.

[siddharthnng]

@Tobey7049 yea right. when you are sitting in calculus final exam with 20 questions to be completed in an hour, go ahead use your "demag" for calculations.

[Tobey7049]

@siddharthnng This trick is not just for sitting in Finals exam using your head, this trick is for anytime anywhere. Once you know this trick, you don't need a calculator. Don't tell me you go to a grocery store carrying your TI-89 calculator with you? So you demag sometimes...or it will get rusty.

[siddharthnng]

@Tobey7049 I don't a " TI-89 calculator" while doing my groceries coz cashiers are there to do that job. idk which grocery store you go to

[jortegaro]

it's more simple and it takes you less time if you just resolve it!

[davi55x]

what was the old way?

[secret00striker]

hmmm koo

[Galaxino]

erm why not just divie 48 by 12 then x12 to the other number?

i mean, we all learnt fractions... why not make it lowest form lol

[jujube4000]

good idea, but there are a lot of steps in this example, which can lead to mistakes, even when the steps are easy. with this problem why not do

50 * 67 = 3350 [67 times 0.5, times 100]

3350 - 134 [134 is 2 times 67, subtracting that brings you back to 48 times 67] = 3216

only 2 steps, and nothing complicated.

i really enjoy your videos though. please keep them coming :)

[jujube4000]

just saw your video "looking for the tens". that seems like a better method to me most of the time.

[Don0chi0cho]

yeh good one but try doing your example in your head not calculator...50 * 67 = 3350 [67 times 0.5, times 100]... we actaully looking for something that you do in your head not using calculator..but i was confuse with your 2nd example..

[jujube4000]

Don0chi0cho: 67 * 0.5 isn't too bad if you look at it the right way. an easy way would be 60/2 + 7/2, or 30 + 3.5, 33.5. so then you have to move the decimal 2 places to the right, because you want 67 * 50 not 67 * 0.5, so the answer is 3350. that's something you can do in your head with a little practice.

[jujube4000]

the 2nd step i was talking about was subtracting 2 * 67 from 50 * 67, which leaves you with 48 * 67.

2 * 67 could be broken down to 2*60 + 2*7, or 120 + 14, 134. subtracting 134 from the 3350 you found earlier gives you 3216. for doing this subtraction in your head it might be easier as 3300-100 and 50-34, then adding those answers together.

[sillemusss]

I LOVE YOU :)

[LEEJIMM]

too many damn steps, lol

[Oajng]

is it only me or it looks like the guy's head is not the same as it's body?

[DonSelvitella]

yah right every math guy lives in a wood cabin it's edited

[benjaminfreak]

i got it lol

[jacobnguy3n]

???

[RnSeeton66]

Ok it works for that problem but lets say you have 47 X 83. You don't have even numbers to subtract by and are not multiples of 3. Are you just screwed then?

[andmaths]

you ought to try with the so-called "russian farmaer method": all you gotta do is multiplicate and divide by 2 (and have a piece of paper): sums are much easier then multiplications

i'll do a vid explaining how to do

[rlsroyce]

Wow. Way too many steps. Try Vedic math. You should be able to get this answer in 4-7 seconds.

[DuangJai99]

easier to do 50x67 which is 3350 and then 2 x 67 is 134..so 3350-134 = 3216... because we know that 5 times any number...we just half the even number that comes before the odd number... this time is 67 which 66 is the even number so half of that is 33. now we know that 5 times any odd number, the ones place will always be 5 so just put the 5 in the ones place which the answer is 335. we multiply by 50 so just put 0 in the ones place and that = 3350. get the idea?