Binary UnitsThe smallest unit of data which can be represented on a computer system is a binary digit or bit .

A bit can have either the value 1 or 0.

1

1

1

1

00

00

Binary UnitsBits are often represented in groups of 8, known as a byte.

10110101

A collection of 1024 bytes is known as a ki lobyte.

Investigate why there are 1024 bytes in a kilobyte instead of 1000.

Binary UnitsWhat comes next? Can you complete the following table?

Unit Value Storage

bit 1 or 0byte 8 bits CharacterKilobyteMegabyteGigabyteTerabytePetabyteExabyteZettabyte

Binary UnitsWhat comes next? Can you complete the following table?

Unit Value Storage

bit 1 or 0byte 8 bits CharacterKilobyte 1024 bytes Half page of textMegabyte 1024 kilobytes Two minute MP3 fileGigabyte 1024 Megabytes One hour movie (approx)Terabyte 1024 Gigabytes 128 DVD moviesPetabyte 1024 Terabytes 7 billion Facebook photosExabyte 1024 Petabytes 50,000 years of DVD videoZettabyte 1024 Exabytes 180 million x Library of Congress

Binary UnitsOr…think about rice…

Unit Value

byte 1 grain of riceKilobyte Cup of riceMegabyte 8 bags of riceGigabyte 3 container lorries of riceTerabyte 2 container ships or ricePetabyte One third of Edinburgh covered in riceExabyte Whole of UK covered in rice - 3 timesZettabyte The entire Pacific Ocean filled with rice

Converting Binary UnitsIn measurement, we wouldn’t say 13500 cm, we would say 135 metres. The same applies to computing units.

Converting from a smaller unit to a larger unit requires division e.g.

120 bits = 120 / 8 = 15 bytes

Converting Binary UnitsIn measurement, we wouldn’t say 13500 cm, we would say 135 metres. The same applies to computing units.

Converting from a smaller unit to a larger unit requires division e.g.

13345 bytes = 13345 / 1024 = 13.03 kilobytes

Converting Binary UnitsIn measurement, we wouldn’t say 13500 cm, we would say 135 metres. The same applies to computing units.

Converting from a smaller unit to a larger unit requires division e.g.

1561235 bytes = 1561235 / 1024 = 1524.64 kilobytes

= 1524.64 / 1024 = 1.489 Megabytes

Converting Binary UnitsConverting from a larger unit to a smaller unit requires mult ipl ication e.g.

3 Terabytes = 3 x 1024 = 3072 Gigabytes

Converting Binary UnitsConverting from a larger unit to a smaller unit requires mult ipl ication e.g.

0.15 Megabytes = 0.15 x 1024 = 153.6 kilobytes

Converting Binary UnitsConverting from a larger unit to a smaller unit requires mult ipl ication e.g.

0.000366 Kilobytes = 0.000366 x 1024 = 0.375 bytes

= 0.375 x 8 = 3 bits