<Tr> <Th> Sestertius </Th> <Td> 1⁄4 </Td> <Td> </Td> <Td> 11⁄4 </Td> <Td> 21⁄2 </Td> <Td> 5 </Td> <Td> 71⁄2 </Td> <Td> 10 </Td> <Td> 6 </Td> <Td> 30 </Td> </Tr> <Tr> <Th> Dupondius </Th> <Td> ​ ⁄ </Td> <Td> ​ ⁄ </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 6 </Td> <Td> 8 </Td> <Td> 4 ​ ⁄ </Td> <Td> 24 </Td> </Tr> <Tr> <Th> As </Th> <Td> ​ ⁄ </Td> <Td> ​ ⁄ </Td> <Td> 1⁄2 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 2 ​ ⁄ </Td> <Td> 12 </Td> </Tr> <Tr> <Th> Semis </Th> <Td> ​ ⁄ </Td> <Td> ​ ⁄ </Td> <Td> 1⁄4 </Td> <Td> 1⁄2 </Td> <Td> </Td> <Td> 11⁄2 </Td> <Td> </Td> <Td> 1 ​ ⁄ </Td> <Td> 6 </Td> </Tr>

What is the cultural and historical significance of roman coins