Multiplication of 2 two-digit numbers where the first digit of both the numbers are same and the last digit of the two numbers sum to 10

Maths Tricks , short cut tricks for maths to make calculation easy and fast

Multiplication of 2 two-digit numbers where the first digit of both the numbers are same and the last digit of the two numbers sum to 10 Let me explain this rule by taking examples To calculate 56×54: Multiply 5 by 5+1. So, 5*6 = 30. Write down 30. Multiply together the last digits: 6*4 = 24. Write down 24. The product of 56 and 54 is thus 3024.: Example.
Understand the rule by 1 more example
78*72 = [7*(7+1)][8*2] = 5616; Is this maths trick helpful? (2840) (845) Post / Read comment (20)

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Rahul (11 years ago)

91*99= how to calculate this?

Like? Yes (7) | No (3)

Nithi (11 years ago)

hi Rahul.. [9*(9+1)][9*1]=[9*10][09]=9009

Like? Yes (8) | No (3)

Nithi (11 years ago)

how to calculate 64*61

Like? Yes (12) | No (4)

upendra singh chahar (11 years ago)

21*21,21*23,41*42,42*43,71*72 etc.
rule is not correct.

Like? Yes (6) | No (4)

Naveen (11 years ago)

@nithi @upendra this rule is for last digit sum will be 10
like
54*56, 51*59, 72*78 etc

Like? Yes (8) | No (2)

Sankarikrishnan (10 years ago)

how to calculate 75*98=?

Like? Yes (1) | No (5)

Anirban (10 years ago)

I guess this one is not correct...Suppose ur multiplying
72*75=5610

43*42= 2006

But in both of the cases the answer is not correct

Like? Yes (4) | No (1)

niranjan pittan (10 years ago)

it is similar to the method squaring the two digit number ends with 5.add 1 with first digit and multiply by first digit write it down and write 25 near to it.
example 25^2=[2*(2+1)] [25] = 6 25. here also the the sum of last two digit is 10.

Like? Yes | No (1)

GAURAV SINGH (10 years ago)

u can also use this trick for 3 digit no like
153*157=(15*16)[3*7]=24021

Like? Yes (2) | No

MONIKA RATHORE (10 years ago)

@sankarikrishan @anirban ghosh this trick if for the numbers whose last digit sum is 10 and @upendra singh chahar 21*21 can be solved by sqaure of two numbers i.e. 21*21=[2^2][1^2]+20*2*1=0401+40=441.

Like? Yes (2) | No (1)

Argha Banerjee (10 years ago)

solve it:-99*98=?

Like? Yes | No

Divyanshu (10 years ago)

how to calculate 24*26=? sum of last two digit is 10...

Like? Yes (1) | No

Smruti Ranjan Sahoo (10 years ago)

can you tell is it applicable for 21*22 , 72*73 ? i think it is not.

Like? Yes | No (1)

Smruti Ranjan Sahoo (10 years ago)

@Monika: thanks i got it.
@Divyansu: yes this rule is applicable to ur question.
24*26 =
[2*(2+1)][4*6] = 624.
i think u got it.

Like? Yes (2) | No

Soumyadeep (10 years ago)

66*64=6*7+6*4=4224 works......

Like? Yes (3) | No

prudhvi vaddi (10 years ago)

what is the answer of 58*46=?

Like? Yes | No (4)

Apoorva Dixit (7 years ago)

74*79 = [7*(7+1)] [4*9] = 5636 , But in real multiplication it should be 5746. So, This Trick is seems to be wrong.

Like? Yes (1) | No (1)

Sert (6 years ago)

Let me come up with easier way;

78*72: 7*7 +(7) : 56 (Multiply first digit of both numbers plus the first common digit number)
8*2 : 16 (Multiply the last digits:
Result is : 5616

Another example to support it;

42*48 : 4*4 + (4) :

Like? Yes | No

Seema (6 years ago)

how to calculate 26*25

Like? Yes | No

Arpan Das (8 Months ago)

I think this is not correct..68*69 not correct

Like? Yes | No

Dimple

India

Punjab

Time: 00:01:33

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Multiplication of 2 two-digit numbers where the first digit of both the numbers are same and the last digit of the two numbers sum to 10

Maths Tricks , short cut tricks for maths to make calculation easy and fast