Roman Numerals / 4

4 in Roman Numerals

IV

4 = IV (4, subtractive). That's IV, using one subtractive pair. 4 splits into 4 (IV), together forming IV. One below 4 is III (3); one above is V (5). At 2 symbols, IV is compact for 4. 4: 1 Arabic digit, 2 Roman symbols, for 4. In binary, 4 is 100, 3 bits long for 4.