The Hindu-Arabic numeral system originated in India and was based on the Brahmi numerals that can be traced back to Budhist inscriptions from the 3rd century BCE. However, it wasn't until the 9th Century CE that the digit 0 was first seen. The system was base-9 until that time, but was nonetheless positional, using spaces to indicate no value.
The Roman numerals LXVII=67 in Hindu Arabic numerals.
The Roman numerals of XXVIII are the equivalent of 28 in Hindu-Arabic numerals
dcccxiii in Roman numerals is equivalent to 813 in Hindu-Arabic numerals.
The Roman numerals of XX are the equivalent of 20 in Hindu-Arabic numerals
The Roman numerals of CCX are the equivalent of 210 in Hindu-Arabic numerals.
The Roman numerals LXVII=67 in Hindu Arabic numerals.
The Roman numerals of XXVIII are the equivalent of 28 in Hindu-Arabic numerals
dcccxiii in Roman numerals is equivalent to 813 in Hindu-Arabic numerals.
Hindu Arabic numerals are the ones we use. 39 is already in Hindu-Arabic numerals.
The Roman numerals of XX are the equivalent of 20 in Hindu-Arabic numerals
The Roman numerals of CCX are the equivalent of 210 in Hindu-Arabic numerals.
The Roman numerals of DCCC are the equivalent of 800 in Hindu-Arabic numerals
12629 is already in Hindu-Arabic numerals
The given numerals are an invalid arrangement of Roman numerals and so therefore there is no equivalent of them in Hindu-Arabic numerals.
In Hindu-Arabic numerals, DCLXII would be 662.
437 is already in Hindu-Arabic numerals
The given Roman numerals can be simplified to CLXVI which is the equivalent of 166 in Hindu-Arabic numerals