101001001 Binary in Octal

Converting a binary number to octal (base 8) without a calculator involves grouping the binary digits into groups of three, and then converting each group to its octal equivalent. Here's a step-by-step guide with an example for binary number 101001001:

Start with the binary number you want to convert to octal. Group the binary digits into groups of three, starting from the right. If the last group has fewer than three digits, pad it with zeros on the left.

Binary: 101 001 001

With Zeros: 101 001 001

Now, convert each group of binary digits to its octal equivalent:

1012 = 58

0012 = 18

0012 = 18

Write down the octal digits obtained from each group:

Octal:511