Square numbers can only have _________ numbers in the unit place.
Square numbers can only have 1, 4, 5, 6 and 9 numbers in the unit place.
If the digit at unit place of a square number is 1, then it is a square of a number___.
If the square root of a number ends in 6 or 4, the given number should have ________ in its units place? With steps.