brahmÄra eka-dine haya caudda manvantara
caudda avatÄra tÄhÄį¹ karena Ä«Åvara
brahmÄra eka-dine - in one day of BrahmÄ; haya - there are; caudda - fourteen; manu-antara - changes of Manu; caudda - fourteen; avatÄra - incarnations; tÄhÄį¹ - in that time; karena - manifests; Ä«Åvara - the Supreme Personality of Godhead.
From this verse it can be calculated that in one month (30 days) of BrahmÄās life there are 420 manvantara-avatÄras and that in one year (360 days) of his life there are 5,040 manvantara incarnations. Thus for the one hundred years of BrahmÄās life, there is a total of 504,000 manvantara-avatÄras. In addition, the Manus themselves are considered partial incarnations of the Supreme Personality of Godhead.