# Reference: Binary to Hexadecimal Conversion Table

 Binary Hex
 0000 0
 0001 1
 0010 2
 0011 3
 0100 4
 0101 5
 0110 6
 0111 7
 Binary Hex
 1000 8
 1001 9
 1010 A
 1011 B
 1100 C
 1101 D
 1110 E
 1111 F

# ASCII to Binary, Part I

Using the ASCII conversion chart (see handout) and the Binary/Hexadecimal table above, answer the following questions.

1. What is the hexadecimal representation for the string "Hello"?

2. What is the binary representation for the string "Hello"?

# Binary to ASCII, Part I

Consider the following binary code:

```01000011 01001111 01001101 01010000 00100000
00110001 00110000 00110111 00100001
```
1. Express the binary code above in hexadecimal (all on one line).

2. If these numbers represent an ASCII string, what string do they represent?

3. If they represent an array of 9 numbers, what are the numbers in the array in decimal notation? (Note:
```        01000011 (binary)
= (4 x 16) + 3  =  64 + 3  =  67
```

# ASCII to Binary, Part II

You are going to think up a word or short phrase in English, encode it in binary, and give it to someone else to decode. Your word or phrase should consist of at least six letters; don't make it too long, both for your sake and for the sake of the person who will decode it. Make sure that it is appropriate to give to anyone else in the class to decode.

2. Express your word or phrase in hexadecimal. (Question: if you chose to represent a phrase, how do you represent the spaces between words?)

3. Express your word or phrase in binary.

4. Copy the binary representation of your word or phrase to another, blank sheet of paper. Make sure to leave spaces between each octet (i.e., leave a space after every eighth binary digit), as was done above. Put your name somewhere on the paper as well.

5. Give the paper containing the binary representation of your word or phrase to another student in the class, following the instructor's instructions. (Don't forget to make sure your name is on the paper.)

# Binary to ASCII, Part II

1. What is the name of the person whose binary representation you are about to decode?

2. Write down the binary representation you received from that person.

3. Express that word or phrase in hexadecimal.

4. Write out the word or phrase in English.