Search your Topic HERE....

August 21, 2013

Shortcut Techniques for multiplication with the numbers ending with 5

Wednesday, August 21, 2013 31 comments

sponsored links

Friends, here are some shortcut techniques for multiplicating with the numbers ending with 5 shared by Mr. Hareesh Kumar. We are very thankful to him for his great support and efforts.


Multiplication With 5 :


EXAMPLES: 123458 * 5 = ?

Solution : 123458*5 = (123458/2) * 10 = 61729*10 = 617290

Example: 224569*5 = ?

Solution: 224569*5 = (224569/2) * 10 = 112284.5 * 10 = 1122845


 
Hence the pattern becomes:

X * 5 = (X/2) * 10



Multiplication with 15:

Example: 124*15 =?

Solution: 124*15 = (124 + (124/2)) * 10

                                   = (124 + 62) * 10 = 1860

Hence the pattern becomes:

X*15 = (X + X/2) * 10 è X*15 = (3X/2) * 10




Multiplication with 25:

Example: 2264 * 25 =?

Solution: 2264*25 = (2264/4) * 100 = 566 * 100 = 56600

Hence the pattern is:

X*25 = (X/4)*100



Multiplication with 35:

Example: 127*35 =?

Solution: 127*35 = (3*127 + (127/2)) * 10

                             = (381 + 63.5) * 10 = 4445

Hence the pattern is:

X*35 = (3*X + X/2) * 10 è X*35 = (7X/2) * 10





Note : The above shown patterns will continue for all the numbers ending with 5. In general we can write this as:

X*n5 = (n*X + X/2) * 10



           Where, n = 0,1,2,3, ………………………………



Some more examples :   
  •  136 * 65 = (6*136 + 136/2) * 10 = (816+68)*10 = 8840 
  • 132*105 = (10*132 + 132/2) * 10 = (1320 + 66)*10 = 13860 
  •  123*55 = (5*123 + 123/2)*10 = (615+61.5)*10 = 6765

 Multiplication of Numbers Ending with 5 and having the difference of 10 : 

Let us assume that there are two numbers X5 and Y5, and the difference between the two numbers is 10. 

Then the multiplication of these two numbers will be :
                 (Larger number of X and Y)2 – 1 | 75

Note : X and Y may be single digit or 2-digit or 3-digit numbers!

EXAMPLES:
1)    35*45 =?
Sol: 35*45 = (42 – 1) |75 = 1575

2)    75*85 = ?
Sol: 75*85 = (82 – 1)|75 = 6375

3)    105*115 = ?
Sol: 105*115 = (112 – 1)|75 = 12075

4)    235*245 = ?
Sol: 235*245 = (242 – 1)|75 = 57575

5)    255*245 = ?
Sol: 255*245 = (252 – 1)|75 = 62475

6)    1055*1045 = ?
Sol: 1055*1045 = (1052 – 1)|75 = 1102475

7)    1125*1135 = ?
Sol: 1125*1135 = (1132– 1)|75 = 1276875
 

31 comments:

  1. shakthiAugust 21, 2013 at 6:29 PM

    awesomeeeeeee!!!!!! thanks a ton hareesh kumar.. grt work....
    really superr...

    ReplyDelete
  2. sirishaAugust 21, 2013 at 6:42 PM

    excellant, thanq for ur guidence...

    ReplyDelete
  3. srinivaskanteAugust 21, 2013 at 6:43 PM

    Very nice

    ReplyDelete
  4. AnonymousAugust 21, 2013 at 6:44 PM

    Excellent thanQ mam...

    ReplyDelete
  5. AnonymousAugust 21, 2013 at 6:50 PM

    awesome

    ReplyDelete
  6. AnonymousAugust 21, 2013 at 8:12 PM

    there is another trick to multiply
    if you have two no in which total of unit is 10 and rest of the rest digits are same eg.23*27 =? find out their mid term ie 25

    then subtract the difference bitween mid term and digit square from square of mid term
    23*27=square(25)-square(2)=625-4 =621
    92*98=7225-9=7216
    104*106=11025-1=11024
    112*118=13225-9=13216

    ReplyDelete
  7. AnonymousAugust 21, 2013 at 8:34 PM

    Multipication by 11: xy*11=x(x+y)y if x+y<10
    if x+y>10 add carry to x
    ex:34*11=3(3+4)4=374
    38*11=3(3+8)8=(3+1)18=418

    ReplyDelete
  8. AnonymousAugust 21, 2013 at 8:40 PM

    thank u so much

    ReplyDelete
  9. AnonymousAugust 21, 2013 at 9:31 PM

    good

    ReplyDelete
  10. kirti joshiAugust 21, 2013 at 9:49 PM

    superb.....superb....and....superb.........thanks....

    ReplyDelete
  11. AnonymousAugust 22, 2013 at 9:08 AM

    Superb!!

    ReplyDelete
  12. UnknownAugust 22, 2013 at 9:59 AM

    SUPERB TECHNIQUES.........THANK U SOOO MUCH AND TELL US THE SHORT CUT FOR FOUR DIGIT MULTIPLICATION...

    ReplyDelete
  13. AnonymousAugust 22, 2013 at 12:23 PM

    superb................

    ReplyDelete
  14. ElixirAugust 22, 2013 at 3:58 PM

    great technique...

    ReplyDelete
  15. AnonymousAugust 22, 2013 at 7:03 PM

    Thanks for guidance

    ReplyDelete
  16. AnonymousAugust 22, 2013 at 7:12 PM

    this site will really go on the top, one day... .. .

    ReplyDelete
  17. AnonymousAugust 22, 2013 at 7:22 PM

    thank u for ur valuable information
    y cant u provide online exams
    hope u will definetly start online exams

    ReplyDelete
  18. AnonymousOctober 29, 2013 at 3:01 PM

    thanks and please post some shortcut techniques for the peoblems on ages

    ReplyDelete
  19. UnknownNovember 6, 2013 at 11:11 AM

    thank u very much for ur support...

    ReplyDelete
  20. UnknownNovember 6, 2013 at 11:11 AM

    thanks

    ReplyDelete
  21. AnonymousNovember 27, 2013 at 2:26 PM

    Awesome...thanx a lot...

    ReplyDelete
  22. AnonymousJanuary 16, 2014 at 9:19 PM

    Thankyou chooooooo much......... it was really helpful :-)

    ReplyDelete
  23. UnknownJanuary 30, 2014 at 7:50 PM

    what about 35*75 if the nos are ending with 5 technique? Math is wrong here...

    ReplyDelete
  24. UnknownJanuary 30, 2014 at 7:51 PM

    what about 35*75 in multiplication of nos ending with 5 technique? solve this right now...? trick fails here...

    ReplyDelete
  25. AnonymousFebruary 21, 2014 at 5:10 PM

    Thanks hareesh kumar...

    ReplyDelete
  26. AnonymousMarch 31, 2014 at 3:46 PM

    thanks for guidance

    ReplyDelete
  27. AnonymousJune 9, 2014 at 11:42 AM

    thanks for this.this very helpful in competitive exams

    ReplyDelete
  28. AnonymousJune 22, 2014 at 8:11 PM

    Hi kresz T, you are asking the multiplication of 2 numbers where both the numbers are ending with 5 but their difference is not 10. That is why above rule fails. Please check again what Hareesh Kumar has mentioned.

    ReplyDelete

Related Posts Plugin for WordPress, Blogger...