When Hindus make a donation or present they never do it with a zero ending sum. Instead a 1 is added to the sum. There is a specific reason for going so.
It is a taboo to present to anyone, on an auspicious occasion, a sum of money with a zero at the end. The auspicious can be marriage, engagement, birth of a baby, house warming, pregnancy relate or a simple gift. The numerical one is always added to the present. Thus one can present rupees 11, 21, 51, 101, 1001 etc but not 10, 20, 50, 100, 1000, etc.
To Hindus, zero means the end of a deal, which is held inauspicious for important occasions, viz., to a priest who performs last rites.