To square a number in which every digit is one. Tricks : Count the number of digits in the given number and start writing numbers in ascending order from one to this number and then in descending order up to one.
(1) (11)² = 121
(2) (111)² = 12321
(3) (1111)² = 1234321
(4) (222)² = (2)² × (111)² = 4 × (12321) = 49284
(5) (3333)² = (3)² × (1111)² = 9 × (1234321) = 11108889
(6) (4444)² = (4)² × (1111)² = 16 × (1234321) = 19749136
(6) (333)² = (3)² × (111)² = 9 × (12321) = 110889
