Caitanya-caritāmṛta 21.20
eka eka gopa kare ye vatsa cāraṇa koṭi, arbuda, śaṅkha, padma, tāhāra gaṇana
[eka eka gopa kare ye vatsa chaarana koti, arbuda, shankha, padma, taahaara ganana]
Blended reading (Sanskrit + English inline)
eka eka gopa kare ye vatsa cāraṇa koṭi, arbuda, śaṅkha, padma, tāhāra gaṇana
“Each of the cowherd boys was tending calves to the extent of a koṭi, arbuda, śaṅkha and padma. That is the way of counting.
Purport
According to Vedic mathematical calculations, the following enumeration system is used: units, tens (daśa), hundreds (śata), thousands (sahasra), ten thousands (ayuta) and hundred thousands (lakṣa). Ten times lakṣa is niyuta. Ten times niyuta is koṭi. Ten times koṭi is arbuda. Ten times arbuda is vṛnda. Ten times vṛnda is kharva. Ten times kharva is nikharva. Ten times nikharva is śaṅkha. Ten times śaṅkha is padma, and ten times padma is sāgara. Ten times sāgara is antya, and ten times antya is madhya, and ten times madhya is parārdha. Each item is ten times greater than the previous one. Thus all the cowherd boys, who were companions of Kṛṣṇa, had many calves to take care of.
— A.C. Bhaktivedanta Swami Prabhupāda
My note
Source: vedabase.io