Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Digital Literacy Computer Basics Computer Basics Binary

The question regards binary numbering. 1st question was 00000001 = 1So what is 00000111

If 00000001 = 1, and 00000011 = 3, What is 00000111?

2 Answers

Steven Parker
Steven Parker
221,330 Points

Here's a method to decode binary numbers. Make a column for each digit, and starting from the right, put a "1" and then as you move left put double the value of the column next to it. Remember, right-to-left (:point_left: THIS WAY :point_left:). You'll get something like this, which is a horizontal version of the helper table shown in the quz:

128  64  32  16   8   4   2   1   <-- 8 columns for 8 digits

Then, put your binary number on the next line, spread into the columns. Now below that, multiply each top number by the binary digit and put the result below. It's easy, since binary digits are either 1 or 0, so you either put the number on top again or zero.

Then finally, add up all the numbers on the bottom row and that's your answer. Using 00000111 for an example:

128  64  32  16   8   4   2   1   <-- starting columns
  0   0   0   0   0   1   1   1   <-- multiply by your binary digits
--- --- --- --- --- --- --- ---
  0   0   0   0   0   4   2   1   <-- add these up:  4 + 2 + 1  =  7

Also, since zeros in front don't count you can skip them. So in this case we really only needed 3 columns.

Saved! Makes sense, and thank you.

Steven Parker
Steven Parker
221,330 Points

stephanie fendley — Glad I could help. You can mark a question solved by choosing a "best answer".
And happy learning!