100010101 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 100010101:

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: 100 010 101

With Zeros: 100 010 101

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

1002 = 48

0102 = 28

1012 = 58

Write down the octal digits obtained from each group:

Octal:425