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My dear friends,
try to do some simple calculations given below within a second…
1)83 multiplied by 87 2)24 multiplied by26 3)72 multiplied by 78 4)99 multiplied by 91 5) 65 multiplied by 65
Tell me how much time did you take to solve them correctly. Let me analyze your reply & then I'll tell you the trick to calculate it within a second!
If you know already don't disclose it here, send me a message.
That's a great trick! I'll use this for sure next time I have to take a test with no calculators allowed, thanks!
this is the trick exclusively applicable to the multiplications of 2 numbers whose digits at unit's place add up to 10 as well as whose digits at tenth's place are same. both of these conditions should be satisfied.
e.g.1)in product of 83 & 87, digit at tenth's place is same i.e.8 & sum of 3 & 7 is 10.
now, follow the rules--
a)firstly, find product of digits at unit's places i.e. here 3 * 7=21.
b)secondly, multiply tenth's place digit by next consecutive number i.e. here 8 * 9=72.
c)now your answer is the outcome in second step i.e.72 followed by outcome in first stepi.e.21
d) hence, your answer is 7221.
In example 3, answer is 7 * 8=56 followed by 2 * 8=16 i.e. 5616.
You should take care that when digits at unit's places are 1 & 9, you must write their product as 09.
considering example 4, answer is 9 * 10=90 followed by 9 * 1=09 i.e. 9009.
now, you can do such specific multiplications orally within a second!
finding the square of two digit numbers is simply superb and easy.. telll me how to find the squares of 3 digit numbers and the square root of the big numbers with decimal points.i m waiting for ur reply
Here is the math behind that wonderful trick:
(10x + y)(10x + 10 - y)=100x2 100x - 10xy +10xy +10y -y2 = 100x2 +100x + 10y - y2 = 10x * 10(x1) + (10-y) * y
plz explain this trick i.i m not getting it
has anyone understood thi trick ?
I took 'xy' as two digit number but it wont give you the correct
result.Say for example 72, so x=7 and y=2 of we substitute the
values there it gvies the result of 72*78
Proof : (10x + y)(10x + 10 - y)
(10*7+2)(10*7+10-2)=72*78…..?
have I mistook the trick…please let me know.
Thanks in advance
i have some tricks in maths
TO FIND A SQUARE OF ANY NUMBER-
let's find square of 12
first identify nearest number like 10 20 30 40 50 …
here it is 10
12-10 is 2 add 12to 2=14 aand multiply by 1 now square the last
digit of 12that is (2)square=4 so your answer is 144
lets find square of 16
16-10=6
16+6=22
and square of 6=36
so answer is 22
36
=256
you can do it by 20 also
20-16=4
now i have to subtract 4 from 16 =12and multiply 12 by 2 since i
have chosen 20 whose first digit is 2; in case of 10 it was 1 so it
was of no problem
so 12*2=24and 6square is 36
so answer is 24
16
=256
in short, for 12 +it's last digit '2' =14
and 2square =4
answer=144
lets try of say 63
63+6=69
69*6=414and square of 3=09
so answer =4149
this trick apply to all in case a 3 digit no. 112 lets say
112+2=114
114*11(first two digit's of 110 are 11)
=1254
and square of 2=04
so answer is 12544
for squares of no. containing last digit 5
example 25
sqaure 5=25 which remains as it is in all cases for finding squares
of 25,35,55,75,65,…..
and multiply first digit by it's following digit
2*(2+1)=2*3=6
answer=625
let's find square of 65
6*7=42
answer=4225(last '25' in all cases)
this is a separate trick for multiplying nos. containing equal
no. of digits but one number must contains all 9's
for example
23*99
write 23 as it is and subtract 1 from last digit that is 3.=3-1= 2
now subtract 2 and 3 separatly from 9
=9-2 and 9-3
=7and 6
so answer is 2(3-1)76
=2276
now add 1 to it final answer=2277
let' multiply
794*999
answer is 79(4-1)(9-7)(9-9)(9-4)
=793205
now add 1 to it =793206
one more example 654789*999999
i m writing final answer you try using same trick
65478(9-1)34521(0+1)
=654788345211
in first bracket "last digit -1"
and in second bracket 'last digit +1"
i also know to find square roots of perfect squares numbers for
example 25 625 169 576 … any number . if you want to learn email me
in june i am free
Oh that's awesome! Sir, you're great, indeed!! You've put that trick in mathematical language within a few minutes!!!
You showed me what to look for - after that it was simple.
Thanks to both of u sir for the great disscussion..
83 * 87 = Multiply last and first digit ( 3*8 = 24) , Multiply First & First Digit ( 8*8 = 64 ), Multiply Last & last digit (3*7 = 21), Multiply First & last digit ( 8*7 =56)
64 & 21 if joined - 6421
Add at exact location
246421
56
----
7221
these mrthods are very smart!!!!!!!!!!!!
what about this When you multiply two numbers in the 90's
together, in parenthesis next to each number put how far that
number is away from 100. Since 92 is 8 away from 100 and 94 is 6
away from 100, the problem 92 × 94 would look like this: 92(8) x
94(6)
Example: 93(7) x 96(4)
Step 1: Add up the numbers in parenthesis 7 + 4 = 11 and subtract
that number from 100. 100 - 11 = 89
Step 2: Multiply the two numbers in parenthesis together and tack
that on to the number from Step 1. 7 × 4 = 28
Answer: 93 × 96 = 8928
i like this method
bt can u tell me whn we multiply an even no or odd no,even or even
no & odd or odd no thn those logic will be put there?
One more simple trick!
83 x 871) find out 100 - 83=17
2) find 100 - 87=13
3) multiply 17 and 13 which gives 221
Thus you have got units place
4) But here we have taken base as 100 which has two 0's so we will
take 2 from 221 as carry over
5) either subtract 83 - 13 or 87 - 7=80
+ carry over(2) =82
So we have got the final answer 8221.
sorry to say .. but ans is 7221 and not 8221 :(
these types of multiplications in which the 1st digit is common and
the sum of the 2nd digits add to 10 can be done as:
8*(8+1) and 3*7 giving 7221
hey its 87-17 & not 7 , & d method is goood….
zwitten(Gaurav), its take more than 5 min, so pls i eagerly wait for ur rpl, pls rpl fast
These methods are easy to understand & use in competetive
examinations.
thanks
this is a very Simple Method to Solve these Questions:-
25*78
=u can write 25 is equal to (100/4)
=(78/4)100
=(19.5)100
=1950
shoiabquadri@gmail.com
see u can do it so simply..shoaib urs idea is r8 too bt nothr simple technique is there… 25×78=1950
5×8=40 so place unit digit 0 and make carry 4. also 2×7=14 nd nw criss cross multiplication will b applicable tat is (2×8)=1635=51 plus previously carried 4 added up to get 51+4=55 so place 5 in tens and carry 5 wich add with (2×7=)14 to get 19..so answer is 1950….. :)
only one or two tricks are help full
this is only complete waste of time
when we multiply any number by 99.for ex.89*99 unit digit
subtract from 10 and ten digit number subtract from 9 and then
write 89-1 u will get the answer.
89
i hav a trik which is very simple for such kind of
problems..look
89*99=
89 is far frm 100 =11
99 is far frm 100=1
11*1=11put on right sideof ur answer
89-1=88 or 99-11=88
so put 88 on left side of ur answer..and u will get..the ans..
8811
i don't understand abt the 11 to the right
Hi,
Can anyone help me with the calculation of greater than 100 by any 3 or 4 digit number? Also, try and put the calculations related to division as well…
u can check divisibilty rule .
eg. if 674 is give and u have to check that it is divisible by any
no. or not.
divisibilty rule of 3 is plus all the digts.eg.6+7+4=17 . the anser
is not divisible by 3 so the no. is also no divisble
hey there is one more method….
if u have a number xxx and you have to check its divisibility by
2,3,5 den this is the trick….
if the number in the tens place of any number is divisible by 2
then that whole number will be divisible by 2.
if the sum of all digits in a number is divisible by 3 then that
whole number is divisible by 3.
and if the number has a 0 or 5 in its tens place then that number
is divisible by 5…
if you want to speed up your calculations then do this:-
(104)whole square then follow steps:--
1)add 104+04= 108 last digit ko hamesha add karna
2) 4 whole suare= 16
3)ans is 10816
it is good but can you tell me the tricks regarding sqares of125 116 212 344 or any number which doesnt come in 100 to 109. i will highly obliged to u.
You likely all know the 10 rule (to multiply by 10, just add a 0 behind the number) but do you know the 11 rule? It is as easy! You should be able to do this one in you head for any two digit number. Practice it on paper first!
To multiply any two digit number by 11:
The only thing tricky to remember is that if the result of the
addition is greater than 9, you only put the "ones" digit in the
hole and carry the "tens" digit from the addition. For example 11 ×
57 … 5__7 … 5+7=12 … put the 2 in the hole and add the 1 from the
12 to the 5 in to get 6 for a result of 627 … 11 × 57 = 627
Practice it on paper first!
EVERY thing IS good…..but if u want to gain complete knowledge on maths….just buy the core vedic math book of SHANKARACHARYA….u can hav everything u want…….
for some sake its coooooooooool .what so ever but still it does
not solve the layman's problem.
for every different problem.one has to remember different
trick.
It is good to rub and polish our brain against that of others.
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is this trick will b apply on digits like 14*14, 25*25 can u tell me