Multiplication Trick for Big Numbers | Faster Mind Calculation Hack

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  • Опубліковано 6 жов 2024
  • This awesome multiplication trick is to multiply numbers near 100 in your mind within 5 seconds. Save this video for your future reference and share it with your friends. Don't forget to subscribe if you want math tricks videos.
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    @Learn.with.Mahbub
    ~-~~-~~~-~~-~
    Please watch: "How to Calculate Faster than a Calculator - Mental Math #2"
    • Mental Math Multiplica...
    ~-~~-~~~-~~-~

КОМЕНТАРІ • 129

  • @HD-fy2wu
    @HD-fy2wu 4 місяці тому +66

    For anyone who's interested why this works:
    Here we have
    (x+y)(x+z)
    = x² + xy + xz + yz
    = x(x + y + z) + yz
    Let x = 100, then we have (100+y)(100+z) = 100(100 + y + z) + yz
    Then y and z are the difference of the numbers to 100 respectively, and 100 + y + z is exactly the sum of one number (100 + y) and that difference of the other (z), where multiplying with 100 adds 2 zeros behind it before summing to yz, the product of that difference, exactly what's been described in the video.

  • @LilPete1
    @LilPete1 7 місяців тому +54

    BRO NEEDS TO BE ON THE NEWS!

  • @Thor__Edits69
    @Thor__Edits69 6 місяців тому +24

    The greatest mathematician for me is Mahbub sir
    You deserve more fame

  • @far8796
    @far8796 7 місяців тому +24

    wow!!!!!!!! i will definitely watch again to memorize this technique, thank you!

  • @Pog303
    @Pog303 7 місяців тому +10

    Thank you I love this it made me doing my homework easier! Thank you I liked and subscribed!! ❤🎉

  • @scientistindianff5969
    @scientistindianff5969 3 дні тому

    Really such a amazing trick!! I loved it! Thank you so much 😊

  • @kpec3
    @kpec3 9 місяців тому +9

    Crazy! I love it!

  • @sircharles9980
    @sircharles9980 Рік тому +5

    Very wonderful trick! Thanks!

  • @Nightowlsfc5251
    @Nightowlsfc5251 5 місяців тому +3

    Thank you for sharing

  • @dinithimenikpura4980
    @dinithimenikpura4980 6 місяців тому +4

    Wow!! Thank you so much!

  • @Bob-Ibn-Bob
    @Bob-Ibn-Bob Рік тому +6

    Cool trick! Thank you!!!

  • @ukrsun
    @ukrsun 7 днів тому

    Thus trick is useful for the numbers close to 100. If you get smaller numbers, then you have a big number to reach 100 and then you have to multiply the difference at some point and numbers are to high to do it fast.

  • @StaticBlaster
    @StaticBlaster 7 місяців тому +3

    Thanks for diz info bruh. dis has saved ma' life.

  • @mushfiqahasan2263
    @mushfiqahasan2263 4 місяці тому +2

    Cant thank you enough for sharing such valuable thing. There's not many channels who's really teaching showing such stuff the way you're doing... 👍👌

  • @smoltsukasa4320
    @smoltsukasa4320 23 дні тому

    God bless you for teaching us things school should have but never these are so damn useful🙏

  • @jagdishkarande474
    @jagdishkarande474 Рік тому +4

    Loved it!
    Much quicker than what I can do.

  • @jerryboi9039
    @jerryboi9039 6 місяців тому +1

    Thank you so much Mahbub i will make sure to use this trick in class!

  • @koshonify
    @koshonify 6 місяців тому +1

    Awesome, it’s soooo useful, thanks!!

  • @demerito
    @demerito 5 місяців тому +1

    Thanks Teacher!

  • @gottipallirajesh2169
    @gottipallirajesh2169 8 місяців тому +53

    How easy to multiply two different number example 45×69 like this??

    • @abdoonyt9049
      @abdoonyt9049 7 місяців тому +30

      69×45
      Ignore 4
      69×5 = (69×0.5)×10 = 34.5×10 = 345 (I wrote it like that to show that, just take half of any number and multiply with 10, when you want to multiply with 5)
      Now focus on 4
      69×4 = 60×4 + 9×4 = 240 + 36 = 276, now add the 0 because you are multiplying with 40 (40 because we already multiplied with 5)
      So, 2760+345 => 3060 + 45 => 3100 + 5 = 3105.
      It looks like a long process but when you get used to these small computation tricks, literally any 2 digit multiplication can be done in the head under 10 seconds

    • @varshasangale9254
      @varshasangale9254 7 місяців тому +5

      45×69
      (-5). (+19)(less/more than 50)
      (Add 45+19 or sub 69-5)ans=64
      64×5=320
      Add one more 0 because of base 10 and sub 19×5 from 3200
      3200-95=3105

    • @tbgbfan2763
      @tbgbfan2763 7 місяців тому +11

      (45x70) - 45

    • @AliciaGrangers
      @AliciaGrangers 6 місяців тому +11

      Let me tell u the fast trick 45 x 69
      Step by step : this method work for all 2 digits number
      First = multiply 5 x 9 it give u 45 now write it 5 and 4 as a carry so don’t write it just write it 5 .
      Second = multiply 9 x 4 it give u 36 and also multiply 5x6 it give u 30 . Now put them together with carry number before which is 4
      It look like this 36+30+4 = 70 and write it zero like this 05 and 7 as a carry so don’t write it 7 only write 0 in front of 5
      Third = multiply 6 x 4 it give u 24 , and then add with carry which is 7 , it look like this 24 + 7 = 31
      So the answer is 3,105
      I hope u understand and do well , good luck 😊

    • @KashitoTsuki
      @KashitoTsuki 6 місяців тому +7

      For 45 x 69, do 45 x 70, then take the 0 off 70. So 45 x 2 = 90, double it again (45 x 4), 180, double it again (45 x 8), 360, then subtract 45 (45 x 7), 315. Then multiply 315 by 10 (45 x 70), 3150, then subtract 45 again (45 x 69). Giving you 3105. This isn’t much of a trick, it’s just simplifying numbers.

  • @hestyreiner9397
    @hestyreiner9397 23 дні тому +3

    What about 97 × 105? If i use this way, the answer is 10285, but when i checked it with calculator the answer is 10185...Please let us know for which numbers we can't work with this method

    • @kaie2420
      @kaie2420 22 дні тому +3

      97 - 100 = -3
      105 - 100 = 5
      Pick 1, then subtract
      105-3 = 102
      Multiply the numbers we found ( -3 & 5)
      -3 x 5 = -15
      Subtract it,
      10200 - 15
      = 10185
      Sorry for my bad explanation, cmiiw.

    • @hestyreiner9397
      @hestyreiner9397 22 дні тому

      ​@@kaie2420now i get it, thank you! You are so helpful

    • @ankitamondal1715
      @ankitamondal1715 3 дні тому

      ​@@kaie2420 👍🏽

  • @maria-elenalaflam4685
    @maria-elenalaflam4685 Рік тому +4

    At 2:10 you say that we multiply one of the numbers by the opposites difference, but aren’t you subtracting? 87-4 = 83, or 96-13= 83. In any case, this is an awesome trick. Thank you very much!

    • @learn.with.mahbub
      @learn.with.mahbub  Рік тому +3

      Hi Maria, You're right. That was my slip of tongue. It is actually subtraction of one number from opposite difference.

  • @rameshchalla938
    @rameshchalla938 Рік тому +2

    very good explanation and thanks for it,

  • @EEG-price
    @EEG-price 7 місяців тому +2

    Genius! 💪

  • @nandithak7175
    @nandithak7175 3 місяці тому +2

    Dude can you provide us some question banks as a HW and comment the solution here ?

  • @mohsinatharrana3458
    @mohsinatharrana3458 Рік тому +2

    Thanks you very much I clearly understood your explanation.
    Amazing concept.

  • @Minhmeo4.0
    @Minhmeo4.0 4 місяці тому

    Thank for this trick mr.geniusmath. I was become a famous boy for defeat my math teacher in calculating now

  • @CodersUnited.orginal
    @CodersUnited.orginal 2 місяці тому

    Thank you dadaa ❤🎉 lots of support

  • @UnknownUser-gv6vw
    @UnknownUser-gv6vw 23 дні тому

    I think I’m becoming a human calculator now, thanks for the tips and tricks Mahbub.

  • @Mecha_Math
    @Mecha_Math 5 місяців тому +1

    Amazing

  • @omanners2389
    @omanners2389 Рік тому +3

    👍👍👍

  • @OleoPauls
    @OleoPauls 15 днів тому

    How do math processes differ in the U.S. and everywhere else?

  • @sudeeptisharma9712
    @sudeeptisharma9712 3 місяці тому

    Woww you made it too easy....

  • @immanuelthangarajan9014
    @immanuelthangarajan9014 Рік тому +2

    It's easy.. thanks

  • @SalmaSaroukh
    @SalmaSaroukh 2 місяці тому

    i dt understand the last on , can u make other examples plzz , and tnx 4 the explanation❤

  • @Mike_Rottchburns
    @Mike_Rottchburns 4 місяці тому

    This is so cool!!

  • @R4y-06
    @R4y-06 5 місяців тому +2

    Is there a reason or proof to be exact why is calculation works? It’s pretty miraculous, although I’m quite interested of why this method of finding the differences and subtracting them, then multiplying them can find the product? Like I don’t understand the link the numbers have with 100 specifically. It doesn’t seem to work if I used 99 or 200 as basis instead, by obvious means.

    • @HD-fy2wu
      @HD-fy2wu 4 місяці тому

      Here we have
      (x+y)(x+z)
      = x² + xy + xz + yz
      = x(x + y + z) + yz
      Let x = 100, then we have (100+y)(100+z) = 100(100 + y + z) + yz
      Then y and z are the difference of the numbers to 100 respectively, and 100 + y + z is exactly the sum of one number (100 + y) and that difference of the other (z), where multiplying with 100 adds 2 zeros behind it before summing to yz, the product of that difference, exactly what's been described in the video.

  • @Nao20244
    @Nao20244 3 місяці тому

    Yo! This is awesome

  • @raskreiak1467
    @raskreiak1467 2 місяці тому +1

    So its again 99x91= 909
    Actual is 9009.
    Just like on the other video. So this must be exceptional.

    • @shiva18editz82
      @shiva18editz82 Місяць тому +2

      Bro if you get only 9 you need to write it as 09
      And same on others if you get 4 you need to write it as 04

  • @Zinebthebest
    @Zinebthebest Рік тому +1

    Its easy thanks

  • @ahmedbhr-ys2dk
    @ahmedbhr-ys2dk 4 місяці тому

    👏👏👏👏

  • @TyKo-h8w
    @TyKo-h8w 7 місяців тому +8

    Is this similar to Harvard university?

  • @dinithimenikpura4980
    @dinithimenikpura4980 6 місяців тому +1

    Can we use this for the multiplication of numbers like 120 by 152?

    • @learn.with.mahbub
      @learn.with.mahbub  6 місяців тому +3

      You can, but that's not suggested. Instead you can do this:-
      (152*100)+(152*10)+(152*10)
      =>15200+1520+1520 = 18240

  • @ikhwanmaulanaramadhansaput9457
    @ikhwanmaulanaramadhansaput9457 3 місяці тому

    hi why is the number when you minus the number, it will be excalyty the same

  • @vedapriya2705
    @vedapriya2705 Рік тому +1

    This method is ok any multiple

  • @fablabguru4235
    @fablabguru4235 Рік тому +1

    If X×X×X=2209.44. what are the values of X?

    • @learn.with.mahbub
      @learn.with.mahbub  Рік тому

      approximately 13. Somewhere between 13.02 and 13.03

    • @Bob-Ibn-Bob
      @Bob-Ibn-Bob Рік тому

      736.48

    • @Bob-Ibn-Bob
      @Bob-Ibn-Bob Рік тому

      Sorry, I was blind - i saw "+" first. >>>>The answer is 13.0245

  • @YUVRAJSingh-yt1eh
    @YUVRAJSingh-yt1eh Рік тому +2

    87×96 = 8352 Ars

  • @Alixnobody
    @Alixnobody 23 дні тому +1

    The second I heard his accent I new I could trust him

  • @gouthamperumal3837
    @gouthamperumal3837 Місяць тому

    2:11 not multiply, add/sub

  • @GauthamGanesh-n7z
    @GauthamGanesh-n7z Рік тому +1

    Does it work with 78*35. Because I am getting the wrong answer.

    • @learn.with.mahbub
      @learn.with.mahbub  Рік тому +6

      Yes, it does work with 78*35. It's 2730. But it's not a good idea to calculate this particular multiplication with this strategy because the difference between 100 and 35 is 65 which is also a big number. You'll have to multiply 65 and 22 at the second step which will be again time consuming.
      So, use some other multiplication strategy for this one. I have already shared some multiplication strategies already in different videos, and will share some in the near future.

    • @nammalwarthiruvengadam2925
      @nammalwarthiruvengadam2925 Рік тому +1

      78 x 35 = 39 x 70 = 2730

  • @harris2433
    @harris2433 5 місяців тому +2

    how about 88*88?

    • @learn.with.mahbub
      @learn.with.mahbub  5 місяців тому

      It works. 7744 is the answer. Try and reply in this comment if you can't get this answer. Then I will show it to you.

  • @galatic86
    @galatic86 6 місяців тому +1

    5:32 Sir pls explain how we got 9400?

    • @xtril059
      @xtril059 2 місяці тому

      (105 - 11) 100 or (89 - 5)100
      Imagine it's just to make the trick. After that we have to subtract the multiplication of the numbers left to 100 of the result.

    • @KhushiSharma-nb3un
      @KhushiSharma-nb3un Місяць тому

      @@xtril059didn’t get it can u explain more clearly please 😕

    • @vanelli6900
      @vanelli6900 23 дні тому

      When the multiplication of the distance numbers result in a negative value, you need to do an additional step before going to the second part of the answer.
      You add two 0's to the first part of the answer and, after that, you subtract. So, for example, 89x105:
      • The distance numbers are -11 and +5 = -55, the second part of the answer.
      • 89 multiplied by +5 = 94, the first part of the answer.
      Simply write 94 and put two zeros: 9400. After that, you subtract by the negative value you got. 9400-55 = 9345.
      The amount of zeros depends on the numbers tho, you'll need to watch out for that.

  • @JuninDuGrao_.
    @JuninDuGrao_. 7 місяців тому

    If the question is 40x50, how can i find the final result?

    • @learn.with.mahbub
      @learn.with.mahbub  7 місяців тому

      4*5 & add 2 zero at the end. 2000

    • @JuninDuGrao_.
      @JuninDuGrao_. 7 місяців тому

      ​@@learn.with.mahbub what if it is 36*54?

    • @learn.with.mahbub
      @learn.with.mahbub  7 місяців тому +4

      36*100 is 3600, half of it is 1800.
      So, 36*50= 1800.
      and, 36*4= 144.
      So, 1800+144=1944.

  • @kaushikbasu9707
    @kaushikbasu9707 Рік тому +1

    8352

  • @amiersapie1549
    @amiersapie1549 6 місяців тому

    I don't get it, how'd you get -13 &-4
    Can someone explain?

    • @learn.with.mahbub
      @learn.with.mahbub  6 місяців тому

      87 is 13 less & 96 is 4 less than 100!

    • @Meanto-cc3qg
      @Meanto-cc3qg 5 місяців тому

      @@learn.with.mahbubhow come it doesn’t work with numbers like 107x125 is it to far away from 100? if so what is the range of how far away from 100 it can be for this to work. I think I found another trick. If the numbers are like 109x133 then you can do the same thing and then add the two numbers in the middle for the correct answer

    • @k-sf1ld
      @k-sf1ld 3 місяці тому

      100 minus 87 is 13;
      100 minus 96 is 4.
      since you're subtracting, it's technically a negative. so, "minus 13" aka -13, and "minus 4" aka -4

  • @BongIdiots-ok5im
    @BongIdiots-ok5im 3 місяці тому

    we got gem

  • @044shraddhajadhav9
    @044shraddhajadhav9 3 місяці тому +4

    This trick doesn't work for all numbers

  • @AnakinCurtBenitez
    @AnakinCurtBenitez 2 місяці тому

    Hello

  • @NikhilKumar-eb3ue
    @NikhilKumar-eb3ue 4 місяці тому

    99*99

  • @sivaarumugam9987
    @sivaarumugam9987 Рік тому

    8532

  • @samthegamer6969
    @samthegamer6969 Рік тому

    Suppose question is 78x 85 then…. Answer should be 6630 while it is coming 63330 using the trick

    • @learn.with.mahbub
      @learn.with.mahbub  Рік тому +7

      Hi Soham, You got an interesting question. Thanks for asking this.
      No, The ans is not 63330, It will be 6630. Let me tell you how!
      The first part is (78-15) =63 & the last part is (-22*-15)=330. We will take last 2 digit in the end part which will be 30. 3 will carry forward to the first part. we will add 3 with 63. (63+3) is 66. So the ans will be 6630.
      Got it?

    • @abdalexMr.360
      @abdalexMr.360 Рік тому +1

      Trick is correct 🤗 wait 💞 Mr. 360 view 🔥. 78×85=6630 ✓ because when,we follow this trick the❣️ differences of multiplication then (22×15=330) then we write ✍️ only last two digits ♣️ is 30 only❣️ and then we do 🎀. 78-15=63❣️ then 63+3(3 come from left of 330) =66 then. ( final answer is 6630 ) ♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️♣️🪄🪄🪄🪄🪄♦️♦️♥️♥️♥️♦️♥️♦️♠️♠️♣️♠️♣️♠️♥️♦️♥️♦️♦️♥️♣️

    • @rameshchalla938
      @rameshchalla938 Рік тому +1

      Since base is considered as 100, only 2 digits( equivalent to number of XEROs in the base)and the third one will be carried and added to Leftside numbers In this query the 3 is added to the 63 making it 66.

    • @nammalwarthiruvengadam2925
      @nammalwarthiruvengadam2925 Рік тому

      78. -22
      85. -15
      =63///330
      =66 80

    • @nammalwarthiruvengadam2925
      @nammalwarthiruvengadam2925 Рік тому

      Sorry it is 6630

  • @Lunaleafylover
    @Lunaleafylover 3 місяці тому +1

    I dont get it

    • @WanHeda-le4xk
      @WanHeda-le4xk 2 місяці тому

      Watch again. It's really helpful