Starter

Converting text to binary

Converting text to binary is a simple process. You simply look up the decimal value for the character in the ASCII table below, and then convert that value from decimal to binary, like we did last lesson.

Example – hello

ascii-hello-example

ASCII Table

DO NOT USE THE HEX COLUMN!!!

Click to enlarge
Click to enlarge

ASCII Table

Converting Binary to Text

Converting from binary to text is nice and simple. You simply convert each binary number to a decimal number and then look up that number on the ASCII table.

ascii-goodbye-example

Convert these text examples to binary:

a. dog

b. cat

c. mouse

Convert these binary examples to text:

d. 01100101 01100111 01100111

e. 01101000 01100001 01101101

f. 01100011 01101000 01101001 01110000 01110011

ASCII

Pros

  • Very easy to read, write and understanding ASCII code, simple for a human being to memorise each character.
  • Small storage and transmission size ( 7 bits for standard ASCII 8bits for extended ASCII)

Cons

Only works for the English language, limited number of special characters.

UNICODE

Pros

Millions of different characters available due to the larger number of bits per character ( 16 or 32 bits)

(Take a look at the full list here)

Cons

2 or 4 times more storage space taken up per letter.

All the ASCII printable characters
An example of a few of hundreds of thousands of Unicode characters available

 

Activity

Log on to Google Classroom and fill out your learning log for the lesson!

Google Classroom

Homework

Complete your lesson 3 learning log

Prep

Download and print 30 copies of the ASCII table.

Starter

Lesson board starter

If students finish before others get them to do the online starter.

Hand out ASCII table to students while they fill in starter.

Demo

Intro ASCII to students by comparing to Morse code and then walk through the process of converting a simple word to binary on the board.

Practice

Get the students to write the first 5 letters of their name in binary.

If the finish get students to have a go at the online practice.

Learning Log

Get students to fill out learning log for lesson 3. When they reach the ASCII limitations bit, stop the class and elicit answers.

Plenary

Lesson review Kahoot