Bits and Bytes

What is a digit?
A digit is a single place that can hold numerical values between 0 and 9. Digits are normally combined together in groups to create larger numbers.

2. “normal” counting numbers used in everyday life a based on what sequence of numbers? The binary number system

3. Where does the word bit originate from?

The word 'bit' was derived from the term binary digit (0 and 1).

4. Binary numbers don’t use base 10. What base do they use? What digits are available in base 2?

Binary numbers use base two. The digits it uses are 0 and 1.

1. Examine the tables below

Base 10

Place Value	10 000	1 000	100	10	1
Place Value	104	103	102	101	100
Digit	9	0	3	0	2
Digit Value	90 000	0	300	0	2

90 302 (base 10) = (9 x 10000) + (3 x 100) + (2 x 1)

If 6,357 can be written as;

(6 * 1000) + (3 * 100) + (5 * 10) + (7 * 1) = 6000 + 300 + 50 + 7

Ø How would you write 4,321

(4*1000)+(3*100)+(2*10)+(1*1)

2. Examine the table below

Base 2

Place Value	16	8	4	2	1
Place Value	24	23	22	21	20
Digit	1	0	1	0	0
Digit Value	16	0	4	0	0

10100 (base 2) = (1 x 16) + (1 x 4) = 20 (base 10)

Ø Write the following numbers in binary (base 2)

21

24

30

3. What is a byte?

A group of binary digits or bits (usually eight) operated on as a unit.

3. How many bytes in a kilo, mega, giga and tera bytes.

Kilo: 1024 bytes

Mega: 1 048 576 bytes

Giga: 1 073 741 824 bytes

Tera: 1 099 511 627 776 bytes

3. Complete the following conversions;

1000 Mb = 0.9765625Gb

500 Gb = 512000Mb

5000 Kb = 4.88281Mb