1. Lesson 2 – Denary to Binary
GCSE Computing – Topic 4
Lesson 2 – Denary to Binary
ASPIRE TO:
construct a 8-bit 2,9,14,1,18,25 number from a 4,5,14,1,18,25 number
CHALLENGE TO:
convert a 8-bit 2,9,14,1,18,25 number to a 4,5,14,1,18,25 number

2. Starter
Try to work out the keywords from the learning objectives and the code below using this simple coding method.
A - 1
B - 2
....
Z - 26
20,8,5  19,13,1,12,12,5,19,20
21,14,9,20  9,19   2,9,20

3. What are Binary Numbers?
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4. Converting Binary to Denary
Each number (1 or 0) is known as a bit, and 8 bits make up a byte. We will be looking ONLY at binary that consists of 8 bits.
To convert the binary number , a table like the one shown above should be created.
Where there is a 1 below the number, that number should be added to any others with a 1 below.
So in this example the answer is =29.

5. Converting Binary to Denary
On your mini-whiteboards convert the following binary numbers to denary: a)
b)111 c)
d)1001

6. Converting Denary to Binary
To convert a number from Denary to Binary the process is reversed.
Watch as you are shown how to convert a denary number to binary, for the example 67.

7. Converting Denary to Binary
On your mini-whiteboards convert the following Denary numbers to binary:
a) 19
b) 26
c) 201
d) 105

8. Task – Binary Game
You will be given a set of questions for level 1. You will need to work in teams to work out the answers.
You will need to convert denary numbers to binary numbers and vice versa.
When you think you have got the answer to the final question for that level, come up to the board, select the level and check your answer. If you got it right move onto the next level.
The questions get progressively harder, you just need to keep converting!

9. Task – Binary Questions
In your books, complete the following questions.
Make sure you show your working.
1. Convert the following numbers from denary to binary.
a) 28  d) 235
b) 72  e) 255
c) 131
2. Convert the following numbers from binary to denary.
a) 1011
b) 11011 c) d)
Extension: Ask for the binary questions worksheet.

10. Plenary
Using your mini-whiteboards, I will display a number either in denary or binary on the board. As fast as you can either convert it from binary to denary or vice versa and hold it up. 42

11. Plenary

12. Plenary

13. Plenary
128

14. Plenary
152

15. Plenary 62

16. Plenary