How_To_Be_Good_At_Math

10 NUMBERS •^ NUMBER SYMBOLS

Number symbols

Since the earliest times, people have used numbers

in their daily lives – to help them count, measure,

tell the time, or to buy and sell things.

Of all these number

systems, only ours has a

symbol for zero. We can also

see that the Babylonian and

Egyptian systems are similar.

This chart shows the

system we use, called

the Hindu-Arabic system,

compared with some other

ancient number systems.

Number systems

A number system is a set of symbols, called numerals, that

represent numbers. Different ancient peoples developed

different ways of writing and using numbers.

Roman numerals

This chart shows the Roman number system, which puts

different letters together to make up numbers.

I II III

Ones I

1

II

2

III

3

IV

4

V

5

VI

6

VII

7

VIII

8

IX

9

Tens X

10

XX

20

XXX

30

XL

40

L

50

LX

60

LXX

70

LXXX

80

XC

90

Hundreds C

100

CC

200

CCC

300

CD

400

D

500

DC

600

DCC

700

DCCC

800

CM

900

Thousands M

1000

MM

2000

MMM

3000

IV

4000

V

5000

VI

6000

VII

7000

VIII

8000

MX

9000

Hindu-Arabic numerals

are used all over the

world today

Numbers were invented

to count amounts of

things such as apples

Many people think the Ancient

Egyptian symbols for 1 to 9

represented fingers

3210

Symbols after a

larger symbol are

added to it

Symbols before a

larger symbol are

subtracted from it

Look at the symbol for six. It’s a V

for 5, with I after it, for 1. This

means “one more than five”, or 5 + 1.

Now look at the symbol for nine.

This time, the I is before the X.

This means “one less than ten” or 10 − 1.

The 10 symbols we use to

make up all numbers are

called digits.

ANCIENT ROMAN

ANCIENT EGYPTIAN

BABYLONIAN

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