To convert a Rupee amount (given in Crores), into its corresponding Dollar amount in Millions, divide the rupee Amount by "Spot Rate", the Current Dollar Rupee rate multiplied by 10.
Thus, Rs 4 Cr = Rs 4,00,00,000/- = 4,00,00,000 / 40 = USD 1 million (assuming the Dollar Rupee Spot rate to be Rs. 40/$
Similarly, Rs 16 Cr = USD 4 million
The idea behind providing this rough and ready conversion method is to help foreigners who may be reading textual articles or financial statements (where amounts are mentioned as "so-many" Crores) in converting these amounts into equivalent Million Dollars.