How i can Design a BCD-to-excess-3 code converter with a BCD-to-decimal decoder and four OR gates?

i dont know

1001+1001

- Constructing a BCD-to-excess-3-code converter with a 4-bitt adder we know that the excess-3 code digit is obtained by adding three to the corresponding BCD digit. To change the circuit to an excess-3-to-BCD-code converter we feed BCD-code to the 4-bit adder as the first operand. Then feed constant 3 as the second operand. The output is the corresponding excess-3 code. To make it a BCD to excess-3 converter, we feed the 2's complement of 3 as the second operand. - Constructing a BCD-to-excess-3-code converter with a 4-bitt adder we know that the excess-3 code digit is obtained by adding three to the corresponding BCD digit. To change the circuit to an excess-3-to-BCD-code converter we feed BCD-code to the 4-bit adder as the first operand. Then feed constant 3 as the second operand. The output is the corresponding excess-3 code. To make it a BCD to excess-3 converter, we feed the 2's complement of 3 as the second operand.