What number should be added to 3439 to make it a multiple of 100?
The multiple of 100 Which is coming after 3439 is 3500. So the number we have to add is 3500 - 3439 = 61
What number should be added to x2+6x to make it a perfect square?
What number should be added to 9x2 + 18 x to make it a perfect square?