Year 8 8.2.4 Units of measure

• Computing
• Lower Secondary (Key Stage 3)

Year 8 8.2.4 Units of measure

Learn how to handle bytes and prefixes and use them to talk about representation sizes.

By the end of this lesson you will:

- Understand how we use different units of measure to represent various values.

- Be able to convert bits and bytes.

- Be able to convert bytes into kilobytes, kilobytes in megabytes.

- Order bytes into size order.

- Understand that data such as ASC art using UTF-8 characters is represented by a number of bytes.

Turn to the person next to you and discuss why do we have different units of measure, we measure long distance in miles not metres why?

Is Binary a base 2 or base 10 system?

1. Base 2
2. base 10

Add together these two binary numbers
010 + 111

1. 121
2. 1111
3. 1001
4. 1101

What is 1001 in decimal?

1. 9
2. 7
3. 2
4. 4

What does the base tell you about the number system?

1 Metre	1000 mm
1 Kilometre	1000 m
1 Kilogram	1000 g
1 Litre	1000 ml

1 KM
1 METRE
1 CM
1000 MM

1000 METRES

10 MM

1 METRE

100 CM

Kilo	K	Thousands
Mega	M	Millions
Giga	G	Billions
Tera	T	Trillions

How do we use this in computing?

What is 5 megabytes in kilobytes?

1. 500
2. 5000
3. 0.5
4. 0.005

How many gigabytes are in a terabyte?

1. 100
2. 1
3. 10
4. 1000

The exception to the *1000 scale is bit to byte!!!

Bits and bytes are not the same

1 byte = 8 bytes

Where before we multiple or divide by 1000 for bits and bytes we do the same operation but with 8

How many bits are in 3 bytes?

1. 3
2. 8
3. 16
4. 24

So this is what a size of 2 GB really means: it is a total of

How do we convert terabytes into gigabytes

how many bits are in 4 bytes?

Smallest

Largest

Organise the objects by size from smallest to largest

Megabyte

Terabyte

Gigabyte

Kilobyte

Byte

Rate how confident you feel converting units of measure

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