What do you think this lesson is all about? Write your answer on a sticky note.

Part 1 Binary Numbers

Part 1: Outcomes I understand why computers need numbers to be represented in Binary. I can count in Binary.

Binary What do you know about binary? What would you like to know about binary?

What are Binary Numbers? (And why does my computer need them?)

Why do humans count in Denary (Base 10)? Why do computers count in Binary (Base 2)?

Counting from 0 to 15 in Binary What do you notice about the number of dots on the cards? How many dots would the next card on the left have?

Part 2 Converting Binary Numbers

Part 2: Outcomes I can convert numbers from Denary to Binary and from Binary to Denary.

Methods for Converting Binary to Denary 1.Trial and error using the ‘Grid Approach’. 2.‘Repeated Division’

The Grid Approach Think of a number … Find the highest number near to it and put 1 in the box below it. Find the remainder and keep the process going until you are finished

The Grid Approach: Example For example, 63 Remainder 5 Remainder 1

The Grid Approach: Try it Out!

The Repeated Division Approach Another method for converting Denary into Binary is repeated division by 2, recording the remainder each time ÷ 2=31Remainder1 31÷ 2=15Remainder1 15÷ 2=7Remainder1 7÷ 2=3Remainder1 3÷ 2=1Remainder1 1÷ 2=0Remainder1

The Repeated Division Approach: Try it Out!

Binary Fun

Binary to Denary

The Land of Computasia In a land far away there is a country where people are still terrorized by dragons. There is no electricity and no technology. The people are protected by knights and wizards who try every day to keep the dragons away from them. People live in villages. Each village is known by the district in which it is based and the number of that village. Villages use bonfires to signal the number of dragons that each village has seen. Health and safety laws mean that no village is allowed to light more than three bonfires at any one time. Use the sheet provided to record the number of dragons each village has seen.

Denary to Binary Bingo

Binary Number Quiz

More Attacks on Computasia! The number of dragon attacks is on the increase and it is feared that there are actually far more than seven dragons in the land. Each village was asked to complete a census of its population and to display this using combinations of flags. Black flags represented 0s and Blue Flags represented 1s. Use the sheet provided to record the census details for each village

Cisco Binary Quiz

Review What have you learnt so far about binary?

Part 3 Adding Binary Numbers

Part 3: Outcomes I can add Binary numbers.

Adding Binary Numbers Adding in binary uses the same approach as in base 10. We add the values and if the value is larger than the column will hold we ‘carry’ a value to the next column. To add 1101 and 1011 in binary: Carried values 1111

Adding Binary Numbers: Try it Out!

Binary Addition Quiz

Part 4 How Text is Stored as Binary

Part 4: Outcomes I can explain how text is stored as Binary numbers. I can convert from Binary to ASCII.

How Text is Stored as Binary When any key on a keyboard is pressed, it needs to be converted into a binary number so that it can be processed by the computer and the typed character can appear on the screen.

A code where each number represents a character can be used to convert text into binary. One code we can use for this is called ASCII. ASCII stands for ‘American Standard Code for Information Interchange’. The ASCII code takes each character on the keyboard and assigns it a binary number. For example: LetterBinary NumberDenary Number a b c ASCII

Coding and Decoding Messages A scout in the borderlands of Computasia has released a coded message. Can you decode it?

Part 5 How Images are Stored as Binary

Part 5: Outcomes I can explain how images are stored as Binary numbers. I can create black and white images in Binary. I can accurately create an image by decoding Binary numbers. I understand how Hexadecimal and RGB are used to represent colours.

How are Images Stored as Binary? Images also need to be converted into binary in order for a computer to process them so that they can be seen on our screen. Digital images are made up of pixels. Each pixel in an image is made up of binary numbers.

How are Images Stored as Binary? If we say that 1 is black (or on) and 0 is white (or off), then a simple black and white picture can be created using binary. What other information is needed in order for the computer to represent the image accurately?

Create Your own Simple Graphic Open up the ‘Binary Image’ worksheet. Create a simple image by shading some squares black and leaving some squares white. If you want the square to be black, type 1 in the square. If you want the square to remain white, type 0 in the square.

Computasia: Image of the Beast! Put your name and date on the worksheet. Answer the first question by putting the binary numbers into the table, and shading in the 1s. You may find it helpful to put a line in the numbers as you do this.

Adding Colour Most images need to use colours as well. Instead of using just 0 and 1, using four possible numbers will allow an image to use four colours. In binary this can be represented using two bits per pixel: – 00 = White – 01 = Blue – 10 = Green – 11 = Red Use this code to fill in the second part of the Computasia: Image of the Beast! If you don’t have the correct colours use W,R,G,B instead.

Hexadecimal Hex codes are used in many areas of computing to simplify binary codes. Computers do not use hexadecimal. Hexadecimal is a shortcut for representing binary. Humans use hexadecimal to shorten binary to a more easily understandable form. Hexadecimal is translated into binary for computer use.

Hexadecimal and Colours Hex can be used to represent colours on web pages and image-editing programs using the format #RRGGBB (RR = reds, GG = greens, BB = blues). The # symbol indicates that the number has been written in hex format. This system uses two hex digits for each colour, e.g. #FF6600.

Hexadecimal and Colours Hex values have equivalents in the RGB colour model. The RGB model is very similar to the hex colour model, but instead of combining hex values you use a value between 0 and 255 for each colour. So an orange colour that is #FF6600 in hex would be 255, 102, 0 in RGB.

Test Your Knowledge! Use the ‘HTML Colour Picker’ at ker.asp. ker.asp Pick a colour and make a note of the Hex and RGB codes in the table on the worksheet. Then use the Shading Tool in MS Word to shade in the ‘Colour’ box with the right shade.