MULTIPLICATION OF A NUMBER BY 11

MULTIPLICATION OF A NUMBER BY 11  

LET US TAKE AN EXAMPLE 63 X 11

WE WRITE 6 AND 3 WITH A GAP AND INSERT (6+3) IN BETWEEN THESE NUMBERS 

 6 [(6+3)] 3

63 X 11 = 6 9 3

36 X 11 = 3 6 9

45 X 11 = 4 9 5

54 X 11 = 5 9 4

45 X 11 = 4 9 5

FINDING THE SQUARES OF A NUMBER ENDING IN 5

FINDING THE SQUARES OF  A NUMBER ENDING IN 5

LET US FIND THE SQUARES OF 25 , 35 , 45 , 55 , 65 , 75 AND SO ON

STEP 1: THE DIGIT IN THE TENTH PLACE IS MULTIPLIED BY ITS SUCCESSOR (2X3,3X4,4X5,5X6) AND WRITE THE NUMBER IN FRONT OF THE QUESTION.

STEP 2: ALONG WITH THE PREVIOUS NUMBER JUST WRITE 25 ON THE RIGHT SIDE TO GET THE SQUARE OF THE NUMBER CONCERNED.

QUICK WAY OF WRITING

QUICK WAY OF WRITING

THE FIRST TEN MULTIPLES OF 19 CAN BE WRITTEN IN THE FOLLOWING WAY

First write the unit digits as 9 8 7 6 5 4 3 2 1 0 and the other digits are 1 3 5 7 9 11 13 15 17 19.

Thus the first ten multiples are 19 38 57 76 95 114 133 152 171 190