Quick Multiplication Technique
Multiplication of Two numbers with the help of one reference Number when both numbers are nearest to each other.
Consider the following example:
MULTIPLY: 96 X 97 =?
Ans: 9312 see trick below.
First step
Take 100 as a reference number since it is nearest to both the numbers. In case of 48*47 we can use 50 as reference number.
Second Step
Find difference from reference no. Subtract 96-100 = -4 and 97-100 = -3
Third step
Then find sum of ist term with the difference from 2nd term and sum of 2nd term with difference of ist term. we will get the same result. i.e. 96-3=93 and 97-4=93. The sum of both must be equal.
Fourth step
Then multiply 93 with the reference no 100. We will get 9300.
Fifth step
Multiply differences as calculated in 2nd step i.e. -4 X-3 gives us +12. Add this 12 with 9300 we will get 9312.
Multiplication of Two numbers with the help of two reference Number when the difference between two nos. is higher.
MULTIPLY: 8 X 37 =?
Ans: 296 see trick below.
First step
Take 10 as a reference number for 8 and 40 as a reference number for 37. Its shows the reference no of 8 is four times the reference number of the 37.
Second Step
Find difference from reference no. Subtract 8 - 10 = -2 and 37-40 = -3
Third step
Then multiply the first difference i.e. -2 by 4 (four times the multiplies of the reference no 10). We get -2 x 4 = -8.
Fourth step
Then add -8 with 2nd number i.e. 37. We get -8 + 37 = 29 and multiply it with main reference number i.e. 29*10= 290.
Fifth step
Multiply differences as calculated in 2nd step i.e. -2 X-3 gives us +6. Add this 12 with 290 as calculated above. we will get 296.