21 Octal in Hex

Converting an octal number to hexadecimal without a calculator involves first converting the octal number to binary, then grouping the binary digits into groups of four, and finally converting each group to its hexadecimal equivalent. Here's a step-by-step guide for octal number21:

Convert each octal digit to its 3-bit binary equivalent:

28 = 0102

18 = 0012

Group the binary digits into groups of four, starting from the right. If the last group has fewer than four digits, pad it with zeros on the left.

Binary: 01 0001

With Zeros: 0001 0001

Convert each group of binary digits to its hexadecimal equivalent:

00012 = 116

00012 = 116