What Is Unit, Number And Numeral? Learn By Example. - Maths Query

As an Amazon Associate we earn from qualifying purchases. Chapter contents

• What is Unit?
• What is Number?
• What is Numeral?
• What are the Numeral Systems?
  • 1. Hindu Arabic Numeral System
  • 2. Roman Numeral System
• Convert Romans into Hindu Arabic
  • 1. Additive Notation
  • 2. Subtractive Notation
• Important rules for roman numbers
• List of Hindu arabic numerals
• List of Roman numerals

FAQs Solved Examples Download & Practice Worksheets Blanks Worksheet True False Worksheet Matching Worksheet Comparing Worksheet MCQ Worksheet Home / Unit / Arithmetic / Number System Unit, Number and Numeral. The Number Systems and Their Rules Topics: Numbers

What is Unit?

Everywhere in our daily life we come across the count of things or number of items, for example 6 pens, 12 bananas, 2 bikes etc. Let’s take “6 pens” to understand what a unit is. “6” refers to count of pens which is a number and the pens can be thought of a thing which is a type of “pen”, which is called as unit. In one more real life scenario of 5 pears in a basket, there is a thing pear and the number of items of type pear are 5. One pear or a pear is a single thing, which is also called a unit.

By definition, a unit is something that denotes a single thing.

Examples of unit

Example 1: 6 pens Here, pen is a single thing, so pen is the unit.

Example 2: a girl The unit is girl

Example 3: 2 days In 2 days, the day is the unit.

What is Number?

Again consider the example of 5 pears in the basket. So a pear is taken five times. Or in other words, a unit (which is pear here) has been taken 5 times, so 5 is called a number.

By definition, a number denotes how many times a unit is taken.

A visit to the shop is worth to see the real life examples of unit and number. The customers buy items in numbers and pay the price for the items to the shopkeeper again in numbers. If a customer bought 6 pens, 12 chocolates and 2 sandwiches then 6, 12, 2 are the numbers. If the customer paid the price $4 for pens, $10 for chocolates and $5 for sandwiches, then 4, 10 and 5 are the examples of numbers.

Examples of number

Example 1: Joseph is nine years old. Here, the unit is a year which is a single thing. The year is taken 9 times. So, nine is a number.

Example 2: There are seven days in a week. The unit is a day which is a single thing. The day is taken 7 times. So, seven is a number.

What is Numeral?

In the above example 1, the number “nine” was used in “Joseph is nine years old”. The number “nine” can be represented using some symbols. Such symbols which can be used to represent the “nine” are called as numerals. In this case “nine” is represented with symbol 9, which is a numeral.

By definition, a numeral is a symbol which is used to represent a number.

Table of numerals from zero to nine

Name	Symbol
Zero	0
One	1
Two	2
Three	3
Four	4
Five	5
Six	6
Seven	7
Eight	8
Nine	9

What are the Numeral Systems?

It is a system used to write numbers using a set of symbols. From the history of mathematics, there were many mathematicians who developed many such systems. The two such famous systems are Roman Numerals and Hindu Arabic System. The Hindu Arabic Number system is the most widely accepted system in the world to write numbers.

1. Hindu Arabic Numeral System

It is the most adapted system in the world. This system was invented by Indian mathematicians between the Ist and 4th centuries. Arabs also started using this system in their Arabic mathematics but after 500 years. Europeans started calling by another name of “Arabic numerals” also when Arabs introduced them the Hindu numerals.

In this system, numerals are represented by the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

Hindu Arabic Numerals

2. Roman Numeral System

This system was invented by Romans. They used 7 letters of Latin alphabets to represent numbers. Each of the letters has a number value. Different combinations of Roman letters can be used to represent any mathematical number.

Roman numerals with their number value

Roman numeral system has no symbol for zero.

Convert Romans into Hindu Arabic

There are two following rules to convert a Roman numeral to Hindu Arabic numeral:

1. Additive notation
2. Subtractive notation

1. Additive Notation

In this notation, the Roman numerals next to each other are added up. There are two cases when these are added up.

First case is when the numerals are repeated next to each other. For example, II, here I is repeated two times next to each other. So, they will be added up which makes 1 + 1 = 2.

Examples of additive notation for repetitive numerals

II = 1 + 1 = 2 III = 1 + 1 + 1 = 3 XX = 10 + 10 = 20 XXX = 10 + 10 + 10 = 30

Second case is when a greater numeral is followed by another smaller numeral. For example, in VI, V has value of 5 and I has a value of 1. So, V is greater than I and V is followed I. Therefore, V and I are added up as 5 + 1 = 6. So, VI is number 6.

Examples of additive notation

VI = 5 + 1 = 6 XIII = 10 + 1 + 1 + 1 = 13 LXII = 50 + 10 + 1 + 1 = 62 CXV = 100 + 10 + 5 = 115

In additive notation, the numerals next to each other are added up when: 1. they are repetitive 2. the first numeral is greater than the second on its right

2. Subtractive Notation

In this notation, the numerals are subtracted. When a smaller numeral is followed by another greater numeral, the smaller is subtracted from the greater. For example, in IV, V has value of 5 and I has a value of 1. So, the smaller I is followed by the greater V. Therefore, I is subtracted from V as 5 – 1 = 4. So, IV is a number 4.

Note

Symbols V, L and D are never repeated.

10 is written as X not VV because V can not be repeated. Also, 100 is written as C not LL because L can not be repeated.

Examples of subtractive notation

IV = 5 – 1 = 4 IX = 10 – 1 = 9 XL = 50 – 10 = 40 XC = 100 – 10 = 90 CD = 500 – 100 = 400

In subtractive notation, the numerals next to each other are subtracted, when: the first is smaller than the next numeral on its right.

Examples of additive and subtractive notations

Example 1: XIV = 10 + (5 – 1) = 10 + 4 = 14

Example 2: XXXIX = 10 + 10 + 10 + (10 – 1) = 30 + 9 = 39

Important rules for roman numbers

There are some following rules those must be followed while forming any roman number.

1. Only I, X, C and M can be repeated in a number. XX = 10 + 10 = 20 ✅ II = 1 + 1 = 2 ✅ VIIII = 5 + 1 + 1 + 1 + 1 = 9 ❌
2. I and X can be repeated maximum three times only. XXI = 10 + 10 + 1 = 21 ✅ VII = 5 + 1 + 1 = 7 ✅ XIIII = 10 + 1 + 1 + 1 + 1 = 14 ❌
3. Symbols V, L and D are never repeated. VV = 5 + 5 = 10 ❌ CC = 100 + 100 = 200 ✅
4. V, L and D are never subtracted. XC = 100 – 10 = 90 ✅ VX = 10 – 5 = 5 ❌
5. The symbol X can be subtracted from L, M and C only. XL = 50 – 10 = 40 ✅ XD = 500 – 10 = 490 ❌
6. The symbol I can be subtracted from V and X only. IX = 10 – 1 = 9 ✅ IL = 50 – 1 = 49 ❌
7. The symbol C can be subtracted from D and M only once. CD = 500 – 100 = 400 ✅ CM = 1000 – 100 = 900 ✅ CCD = 500 – 100 – 100 = 300 ❌
8. If a bar is placed over a numeral, that shows that it will be multiplied by 1000. V = 5 × 1000 = 5000 ✅ X = 10 × 1000 = 10000 ✅

List of Hindu arabic numerals

1 to 100

1	11	21	31	41	51	61	71	81	91
2	12	22	32	42	52	62	72	82	92
3	13	23	33	43	53	63	73	83	93
4	14	24	34	44	54	64	74	84	94
5	15	25	35	45	55	65	75	85	95
6	16	26	36	46	56	66	76	86	96
7	17	27	37	47	57	67	77	87	97
8	18	28	38	48	58	68	78	88	98
9	19	29	39	49	59	69	79	89	99
10	20	30	40	50	60	70	80	90	100

List of Roman numerals

1 to 20

I	1	XI	11
II	2	XII	12
III	3	XIII	13
IV	4	XIV	14
V	5	XV	15
VI	6	XVI	16
VII	7	XVII	17
VIII	8	XVIII	18
IX	9	XIX	19
X	10	XX	20

21 to 40

XXI	21	XXXI	31
XXII	22	XXXII	32
XXIII	23	XXXIII	33
XXIV	24	XXXIV	34
XXV	25	XXXV	35
XXVI	26	XXXVI	36
XXVII	27	XXXVII	37
XXVIII	28	XXXVIII	38
XXIX	29	XXXIX	39
XXX	30	XL	40

41 to 60

XLI	41	LI	51
XLII	42	LII	52
XLIII	43	LIII	53
XLIV	44	LIV	54
XLV	45	LV	55
XLVI	46	LVI	56
XLVII	47	LVII	57
XLVIII	48	LVIII	58
XLIX	49	LIX	59
L	50	LX	60

61 to 80

LXI	61	LXXI	71
LXII	62	LXXII	72
LXIII	63	LXXIII	73
LXIV	64	LXXIV	74
LXV	65	LXXV	75
LXVI	66	LXXVI	76
LXVII	67	LXXVII	77
LXVIII	68	LXXVIII	78
LXIX	69	LXXIX	79
LXX	70	LXXX	80

81 to 100

LXXXI	81	XCI	91
LXXXII	82	XCII	92
LXXXIII	83	XCIII	93
LXXXIV	84	XCIV	94
LXXXV	85	XCV	95
LXXXVI	86	XCVI	96
LXXXVII	87	XCVII	97
LXXXVIII	88	XCVIII	98
LXXXIX	89	XCIX	99
XC	90	C	100

Frequently Asked Questions

1) Which numeral system is mostly used in the mathematics?

The Hindu Arabic numeral system is most commonly used in mathematics.

2) Who has invented roman numbers?

Roman numbers were originated in ancient Rome.

3) What is the symbol for zero in roman numerals?

There is no symbol for zero in roman numerals.

4) What is Hindu Arabic numerals?

The Hindu Arabic Numeral system is a positional base ten number system for numbers. It is also known as Indo Arabic Numeral system

Solved Examples

Write the following numbers in roman numerals.

1. 175
2. 92
3. 399
4. 450
5. 725
6. 287
7. 79
8. 99
9. 50000
10. 18235

1. 175 175 = 100 + 70 + 5 = C + L + XX + V = CLXXV
2. 92 92 = 90 + 2 = (100 - 10) + 2 = XC + II = XCII
3. 399 300 = 300 + 90 + 9 = CCC + XC + IX = CCCXCIX
4. 450 450 = 400 + 50 = CD + L = CDL
5. 725 725 = 700 + 20 + 5 = DCC + XX + V = DCCXXV
6. 287 287 = 200 + 80 + 7 = CC + LXXX + VII = CCLXXXVII
7. 79 79 = 70 + 9 = 50 + 20 + 9 = L + XX + IX = LXXIX
8. 99 99 = (100 - 10) + 9 = XC + IX = XCIX
9. 50000 50000 = 50 × 1000 = L
10. 18235 18235 = 18000 + 200 + 35 = 18 × 1000 + 200 + 35 = XVIII + CC + XXXV = XVIIICCXXXV

Fill in Blanks Worksheet

Type:	Blanks
Count:	1

S.N.	Roman number	Hindu Arabic number
1)	L	___________
2)	___________	22
3)	___________	89
4)	XC	___________
5)	___________	40
6)	___________	99
7)	LXXVII	___________
8)	LI	___________
9)	___________	25
10)	XCI	___________

Blanks PDF Worksheet Download

Write True or False Worksheet

Type:	True False
Count:	1

S.N.	Statement	✓ or ✕
1)	XII + X = 32
2)	XCIX + I = 100
3)	X stands for 10000
4)	XC + L = 50
5)	M stands for 1000
6)	V, L and D can never be subtracted.
7)	LX + XL = 100
8)	C can be subtracted from D and M only once.
9)	220 = CCCX
10)	X can be subtracted from L and C only once.

True False PDF Worksheet Download

Match Columns Worksheet

Type:	Matching
Count:	1

Hindu Arabic number		Roman number
1)	100	a)	LV
2)	32	b)	LXIV
3)	49	c)	XCIV
4)	5d	d)	XXXII
5)	64	e)	C
6)	94	f)	XLIX

Matching PDF Worksheet Download

Compare Columns Worksheet

Type:	Comparing
Count:	1

Put >, < or = in the boxes.

1)	99	XCIX
2)	24	XX
3)	XLII	XLIII
4)	LXXX	XCIX
5)	CX	C
6)	LV	60
7)	130	XC
8)	XC	90
9)	LXXX	99
10)	55	L

Comparing PDF Worksheet Download

Multiple Choice Questions Worksheet

Type:	MCQ
Count:	1

1) The roman numeral for 50 is

1. X
2. L
3. C
4. V

2) The roman numeral for 98 is

1. XCVIII
2. XCVII
3. LXXXX
4. LXXXXVIII

3) The hindu arabic numeral for CX is

1. 100
2. 150
3. 111
4. 110

4) XVI + XIV = ?

1. XXVVII
2. XXX
3. XXVII
4. XXVVI

5) The roman numeral for 400 is

1. XD
2. DX
3. DC
4. CD

6) Year 2024 is written as

1. MXXXV
2. MMXXV
3. MMXXIV
4. MMXXX

7) V stands for

1. 50
2. 500
3. 5000
4. 50000

8) L stands for

1. 500
2. 5000
3. 50000
4. 50

9) C + XC + VII = ?

1. CXCVII
2. CCXVII
3. CXVCII
4. XCCVII

10) 90 in roman numeral is written as

1. LXXXX
2. LXXX
3. XC
4. CX

MCQ PDF Worksheet Download Back to Number System Last updated on: Nov 17, 2025 Share on:

Related chapters

List of Types of Numbers Used in Maths with Examples

Digit, Face, Place Values and Comparison of Numbers

Prime Numbers with Sieve of Eratosthenes Test

Answer Keys Buy Maths Books

Buy related Maths books for USA

Grade 2

Grade 2 Books

Grade 3

Grade 3 Books

Grade 4

Grade 4 Books

Buy related Maths books for India

Class 4

Class 4 Books

Class 5

Class 5 Books

Class 6

Class 6 Books

Maths web stories

Arithmetic Do you know?

A Quick Tour on Roman Numbers & Rules to Write

Search lessons in units

ARITHMETIC

ALGEBRA

GEOMETRY

STATISTICS

THINGS TO REMEMBER

KNOWLEDGE

Search lessons by topic

2D Shapes

Angles

Area Perimeter

Coordinate Geometry

Decimals

Factorization

Fractions

Lines

Numbers

Rounding off