easy multiplication of two digit number

here we can learn how to multiply two numbers easily 

let us take two numbers 86*84 then we get 7224

as it so simple that 

1. first we should check the sum of ones place of both the numbers are equal to ten (6+4=10)

      2.then we should check both the tens place of the number are same (8,8)

     3.now multiply ones place of  both numbers (6*4=24)

     4.now for tens place apply n(n+1) i.e 8(8+1)=8*9=72

       

     5.now join together 7224 it is so simple

eg.2  now check another problem 72*78