binary-coded decimal
class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four or eight. Special bit patterns are sometimes used for a sign or for other indications
Aiken code
complementary binary-coded decimal which assigns a group of 4 bits to each decimal digit: 0→0000, 1→0001, 2→0010, 3→0011, 4→0100, 5→1011, 6→1100, 7→1101, 8→1110, 9→1111