Be wise while counting

Be wise while counting
One day in Akbar’s court someone asked the question, "How many crows are there in the city?", No one had the answer.
Birbal quickly replied "Four thousand three hundred and twelve". He was asked how did he know this?
Birbal send " Send your man out to count the crows. If it is lesser than this number then some crows are visiting their families elsewhere and if it is more than this number, then some crows from outside are visiting their families here. Akbar was very happy with the answer and showered Birbal with gifts for his wit.