Try This at Home:
Can you “speak” like a computer to encode your initials using binary?
What you’ll need:
- Beads, especially black and white
- String or cord, about 15 inches
- Ruler or measuring tape
Here’s what to do:
- Ask an adult to help you cut a piece of string or cord that is about 15 inches long.
- Fold the cord in half and tie a knot that leaves a small loop at the top and gives you two tails of cord.
- Separate your beads into piles of black, white, and colors.
- Look at the chart below and find your first and last initial. Notice that each letter will require eight beads. This chart is a representation of Extended ASCII, a code that uses eight binary digits (aka bits) per symbol. In computing, eight bits equal a byte.
- Line up black and white beads in the order of your first initial. You should have 8 beads. Thread the beads onto one of the two pieces of cord. At the end, you can add a colored bead for fun and to add some color, but you don’t have to. Tie a knot on the end of the cord to hold your beads in place.
- Line up black and white beads in the order of your last initial, and thread them onto the other piece of cord. Again you can add a colored bead. Tie a knot on the end.
- Trim off any excess cord from each side.
- Now you can attach the loop to a key ring to make a keychain or you can put it on another piece of string or cord to make a necklace!
Take it further:
- Can you think of another way to represent the binary code of your initials? Could you use different colors? Different materials?
- Share the chart in the instructions and your keychain with a friend or family member and challenge them to decode it. Ask them to challenge you too! Which two initials are in the keychain in the picture above?
- Try writing a three letter word like “cat” in binary code! You can use beads or color in squares on paper or use the numbers “0” and “1”. (Note: Using the chart included above, black=0 and white=1.) How many bits does it take? How many bytes?
- Try making a necklace of your full first name in binary using beads. You can add a colored bead in-between letters if you want some extra color, but the code doesn’t require them since we know each letter is eight bits long. Challenge someone to “read” your code.
- Can you decode the word in this picture using the chart above? Note that we used green and purple beads instead of black and white, respectively.
What’s going on?
Binary code is a way of representing information using only two options. There are many ways to represent a binary code, but in computing it is often discussed using zeros (0) and ones (1). This seemingly simple system can be used to store all kinds of information on computers. At the most basic level, binary can be thought of as code of “off” and “on” that a computer reads to complete tasks. There are different types of binary codes, known as encoding schemes that convert complex information into a code that uses only two options. In this project, we used a common encoding scheme for converting letters of the English alphabet into binary numbers like a computer reads.
The American Standard Code for Information Interchange commonly referred to as ASCII (pronounced as-skee) is an encoding scheme for converting the English alphabet, numbers, and some common symbols into binary using “0” and “1.” ASCII was developed in the 1960s based on codes used in telegraph communications. In this project, we used the Extended ASCII encoding scheme which uses 8 bits (aka a byte) for each character, so the capital letter “A” for example is represented as “01000001” or, as in our table, “black, white, black, black, black, black, black, white” or in terms of off/on like a switch “off, on, off, off, off, off, off, on.”
Other encoding schemes do not use exactly 8 bits (or 1 byte) of code for each symbol, so it can be harder to tell when one symbol ends and the next begins. In this case, the code will include delimiters or extra characters that signal the end of a symbol and serve to separate the code so the computer can read it correctly. Computers also use other types of binary codes to store information. For example, hard disk drives use magnetic positive and negative to store information. Can you think of any examples of binary codes you may have used? Yes or no?