# Unit Overview: Data Representation

## Lessons:

9 lessons

### What is representation?

In this lesson, we will consider two-state systems, such as bulbs and switches, and investigate how combining these in groups provides more combinations. Finally, we will learn how this relates to computers, and will be introduced to binary.

• 1 Quiz
• 12m Video
• Presentation(PPT)
• Worksheet
• Transcript

### Number bases

In this lesson, we will use decimal representation to explore the concept of place values in number bases and the values of digits. Then, we will explore the representation of binary values, and converting these back to decimal.

• 2 Quizzes
• 15m Video
• Presentation(PPT)
• Transcript

### Binary maths

In this lesson, we will discover how to perform binary shifts, binary addition and develop an understanding of the term 'overflow'.

• 2 Quizzes
• 25m Video
• Presentation(PPT)
• Transcript

In this lesson, you will be introduced to the hexadecimal number system and learn how to convert between hexadecimal and decimal numbers. We will also learn why hexadecimal is used.

• 2 Quizzes
• 16m Video
• Presentation(PPT)
• Transcript

### What can you remember?

In this lesson, we will recap our previous learning on data representation within this unit to see how much we can remember. We will review number bases, binary maths and hexadecimal.

• 2 Quizzes
• 10m Video
• Presentation(PPT)
• Transcript

### Representing text

In this lesson, we will look at character coding systems. First, we will consider character coding systems that you might have come across before, such as semaphore and Morse code, then we will be introduced to ASCII, a standard coding system for representing text. Next, we will learn about the need for Unicode to extend ASCII. Finally, we will learn how to work out the size of a plain text file.

• 1 Quiz
• 14m Video
• Presentation(PPT)
• Worksheet
• Transcript

### Representing bitmap images

In this lesson, we will learn how bitmap images are represented in binary. We will learn about resolution, bit depth and how to calculate the file size of a bitmap image.

• 1 Quiz
• 8m Video
• Presentation(PPT)
• Worksheet
• Transcript

### Representing sound

In this lesson, we will look at sound and think about how it could be represented for storage or transmission. We will investigate the effect of sound waves in the air and how this relates to speakers and microphones. We will sample a short sound wave in order to understand this representation and how it can be improved on. We will also calculate representation size from sample rate, size, and duration.

• 1 Quiz
• 11m Video
• Presentation(PPT)
• Worksheet
• Transcript

### Units of measurement

In this lesson, we will look at units of measurement and learn how to convert between these units.

• 1 Quiz
• 10m Video
• Presentation(PPT)
• Transcript