Back to 课程

Computer Science GCES OCR

0% Complete
0/0 Steps
  1. Cpu Architecture Performance And Embedded Systems Ocr
    5 主题
  2. Primary And Secondary Storage Ocr
    6 主题
  3. Data Storage And Compression Ocr
    12 主题
  4. Networks And Topologies Ocr
    6 主题
  5. Wired And Wireless Networks Protocols And Layers Ocr
    6 主题
  6. Identifying And Preventing Threats To Computer Systems And Networks Ocr
    2 主题
  7. Operating Systems And Utility Software Ocr
    2 主题
  8. Ethical Legal Cultural And Environmental Impact Ocr
    2 主题
  9. Computational Thinking Searching And Sorting Algorithms Ocr
    3 主题
  10. Designing Creating And Refining Algorithms Ocr
    5 主题
  11. Programming Fundamentals And Data Types Ocr
    5 主题
  12. Additional Programming Techniques Ocr
    7 主题
  13. Defensive Design And Testing Ocr
    6 主题
  14. Boolean Logic Diagrams Ocr
    2 主题
  15. Programming Languages And Integrated Development Environments Ides Ocr
    3 主题
  16. The Exam Papers Ocr
    2 主题
  17. Structuring Your Responses Ocr
    3 主题
课 Progress
0% Complete

Exam code:J277

Denary to Binary Conversion

What is denary?

  • Denary is a number system that is made up of 10 digits (0-9)

  • Denary is referred to as a Base-10 number system

  • Each digit has a weight factor of 10 raised to a power, the rightmost digit is 1s (100), the next digit to the left 10s (101) and so on

  • Humans use the denary system for counting, measuring and performing maths calculations

  • Using combinations of the 10 digits we can represent any number

1-1-number-systems-number-systems-1-ib-computer-science-revision
  • In this example, (3 x 1000) + (2 x 100) + (6 x 10) + (8 x 1) = 3268

  • To represent bigger number we add more digits

What is binary?

  • Binary is a number system that is made up of two digits (1 and 0) 

  • Binary is referred to as a Base-2 number system

  • Each digit has a weight factor of 2 raised to a power, the rightmost digit is 1s (20), the next digit to the left 2s (21) and so on

  • Using combinations of the 2 digits we can represent any number

uCiRLNB9_1-1-number-systems-number-systems-2-ib-psychology-revision
  • In this example, (1 x 8) + (1 x 4) = 12

  • To represent bigger numbers we add more binary digits (bits)

128

64

32

16

8

4

2

1

27

26

25

24

23

22

21

20

Why do computers use binary?

  • The CPU is made up of billions of tiny transistors, transistors can only be in a state of on or off

  • Computers use binary numbers to represent data (1 = on, 0 = off)

Examiner Tips and Tricks

Don’t forget to show your working! Data conversion questions will often be worth 2 marks, 1 for the answer and 1 for your working

Denary to binary conversion

  • It is important to know the process of converting from denary to binary to understand how computers interpret and process data

Example 1

  • To convert the denary number 45 to binary, start by writing out the binary headings from right to left

128

64

32

16

8

4

2

1

 

 

 

 

 

 

 

 

  • Start at the leftmost empty column heading (128). Is the denary number > column heading? (45 > 128) No, put a 0 in the 128 column. Repeat until you put a 1 under a heading. In this example it would be 32

128

64

32

16

8

4

2

1

0

0

1

 

 

 

 

 

  • Next subtract column heading from denary value, 45-32 = 13

  • Repeat previous two steps until you have a value under each column heading

128

64

32

16

8

4

2

1

0

0

1

0

1

1

0

1

  • 32 + 8 + 4 + 1 = 45

  • Denary 45 is 00101101 in Binary

Examiner Tips and Tricks

At GCSE you will only be asked to convert from/to binary up to and including 8 binary digits (8 bits). That means you are working with a denary range of 0-255 (00000000-11111111)

Example 2

  • To convert the denary number 213 to binary, start by writing out the binary headings from right to left

128

64

32

16

8

4

2

1

 

 

 

 

 

 

 

 

  • Start at the leftmost empty column heading (128). Is denary number > column heading? (213 > 128) Yes, put a 1 under the heading.

<td class=”border border

128

64

32

16

8

4

2

1

1

 

 

 

 

 

 

Responses

您的邮箱地址不会被公开。 必填项已用 * 标注