Counting numbers and their spellings

Counting Numbers:

The counting numbers and their spellings are mentioned below.

1	One
2	Two
3	Three
4	Four
5	Five
6	Six
7	Seven
8	Eight
9	Nine
10	Ten
11	Eleven
12	Twelve
13	Thirteen
14	Fourteen
15	Fifteen
16	Sixteen
17	Seventeen
18	Eighteen
19	Ninteen
20	Twenty
30	Thirty
40	Fourty
50	Fifty
60	Sixty
70	Seventy
80	Eighty
90	Ninty
100	Hundred
1000	One Thousand
10000	Ten Thousand
100000	One Lac
1000000	Ten Lac
10000000	One Crore
100000000	Ten Crore

Color names and their spellings

Name Of The Colors:

The colors are divided in three main categories. The Primary, Secondary and Tertiary. There are three basic (Primary) colors. The Primary colors are RYB (Red, Yellow, Blue). The other colors are made by mixing these basic colors. The color names and their spellings are mentioned below.

Name Of The Primary Colors:

1. Red
2. Yellow
3. Blue

Name Of The Secondary Colors:

1. Green
2. Orange
3. Purple

Name Of The Tertiary Colors:

1. Yellow-Orange = [Marigold]
2. Red-Orange = [Vermilion]
3. Red-Purple = [Magenta]
4. Blue-Purple = [Violet]
5. Blue-Green = [Teal]
6. Yellow-Green = [Lime Green]

Name of the planets and their spellings

Name Of The Planet:

There are nine planet in our solar system. The Sun is the center of the solar system. The planet names and their spellings are mentioned below.

1st planet of solar system: Sun

2nd planet of solar system: Mercury

3rd planet of solar system: Venus

4th planet of solar system: Earth

5th planet of solar system: Mars

6th planet of solar system: Jupiter

7th planet of solar system: Saturn

8th planet of solar system: Uranus

9th planet of solar system: Neptune

Month names and their spellings

Name Of The Months:

There are twelve months in a year and the first month of the year is January. The month names and their spellings are mentioned below.

1st month of the year: January

2nd month of the year: February

3rd month of the year: March

4th month of the year: April

5th month of the year: May

6th month of the year: Jun

7th month of the year: July

8th month of the year: August

9th month of the year: September

10th month of the year: October

11th month of the year: November

12th month of the year: December

Day names and their spellings

Name Of The Days:

There are seven days in a week and the first day of the week is Sunday. The day names and their spellings are mentioned below.

1st day of the week: Sunday

2nd day of the week: Monday

3rd day of the week: Tuesday

4th day of the week: Wednesday

5th day of the week: Thursday

6th day of the week: Friday

7th day of the week: Saturday

CBSE board Class 6 math : Chapter 1 - Knowing numbers from unit Number System

Number System

Knowing Numbers:

Natural Numbers: Counting numbers are called as natural numbers.

Denote as N= { 1,2,3,4,5,6,7,8,9 }

1

2

3

4

5

6

7

8

9

Whole Numbers: If zero is included in the set of natural numbers known as whole numbers.

Denote as W= { 0,1,2,3,4,5,6,7,8,9 }

0

1

2

3

4

5

6

7

8

9

The numbers are written with the help of symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 knows as digits.

Expressing a number: Right to left

10x10x10x10	10x10x10	10x10	10	1
Ten Thousand	Thousand	Hundred	Ten	Ones

Example: 67138

Sixty Seven Thousand One Hundred Thirty Eight

6	7	1	3	8
Ten Thousand	Thousand	Hundred	Ten	Ones

= 6 x 10000 + 7 x 1000 + 1 x 100 + 3 x 10 + 8 x 1

= 60000 + 7000 + 100 + 30 + 8

= 67138

Comparing and Ordering:

Comparison of numbers starts from first digit of numbers from the left to right hand side.

Example 1: Compare 8534 and 8713

Number 1	Number 2	Compare
8	8	8 = 8	Compare next digit
5	7	5 < 7	Stop Comparing

Number 8713 > Number 8534

Example 2: Compare 4635 and 4619

Number 1	Number 2	Compare	Steps
4	4	4 = 4	Compare next digit
6	6	6 = 7	Compare next digit
3	1	3 > 1	Stop Comparing

Number 4635 > Number 4619

Successor and Predecessor:

Successor of number is finding by adding 1 to the number.

Successor = Number + 1

Predecessor of number is finding by subtracting by 1 to the number.

Predecessor = Number - 1

Successor = Number + 1

Periods – The Indian System of Numeration:

Periods	Crores		Lakhs		Thousands		Ones
Places	Ten Crores	Crores	Ten Lakhs	Lakhs	Ten Thousands	Thousands	Hundreds	Tens	Ones
	TC	C	TL	L	T-Th	Th	H	T	O
	100000000	10000000	1000000	100000	10000	1000	100	10	1
Example: A number write as 64,32,96,563

*A comma is put after first three digits then after every two digits start from right.

Example: A number 643296563 is write as 64,32,96,563

Periods – The International System of Numeration:

Periods	Billions			Millions			Thousands			Ones
Places	Hundred Billions	Ten Billions	Billions	Hundred Millions	Ten Millions	Millions	Hundred Thousands	Ten Thousands	Thousands	Hundreds	Tens	Ones
	HB	TB	B	HM	TM	M	H-Th	T-Th	Th	H	T	O
	100000000000	10000000000	1000000000	100000000	10000000	1000000	100000	10000	1000	100	10	1
	1011	1010	109	108	107	106	105	104	103	102	101	100

*A comma is put after every three digits from the right.

Example: A number 74543231782 is write as 74,543,231,782

Note: One Trillion is 1000 billion.

Use of Numbers in daily life:

Numbers are used to measuring the length, distances, weights and amounts.

Small lengths are measured in millimeter (mm) and centimeter whereas larger lengths are measured in meter (m) and kilometer (km).

1 Meter (M) = 100 cm (centimeter) = 10000 mm (millimeter)

1 Kilometer = 1000 M x 1000 = 1000000 mm

1 Gram = 1000 mg and 1 kg (Kilogram) = 1000 gm (gram)

1 Kilogram = 1000 gm x 1000 = 1000000 mg (milligram)

1 Liter (L) = 1000 ml and 1 kL (Kiloliter) = 1000 L

1 Kiloleter = 1000 L x 1000 = 1000000 ml (milliliter)

Roman Numerals:

The Romans symbols are:

Roman Symbols	I	V	X	L	C	D	M
Meanings	1	5	10	50	100	500	1000

Example: Can be calculated as:

III = 1 + 1 +1 = 3

XXX = 10 + 10 + 10 = 30

CC = 100 + 100 = 200

CCC = 100 + 100 + 100 = 300

MM = 1000 + 1000 = 2000

Exercise:

Question 1: Write the natural numbers?

Question 2: Write the whole numbers?

Question 3: Zero is neither positive nor negative (True / False)?

Question 4: Write the number 35409 in numerals?

Question 5: Compare the number 67518 and 67499?

Question 6: Write the number 3558409 in numerals?

Question 7:  Fill in the blanks

(a) 1 Meter = _____ Centimeter

(b) 1 KM = _______Meter

(c) 1 KG = _______ gm

(d)1 KL = _______ ml

Question 8: Fill in the blanks

(a)  VI = ______

(b) XI = _______

(c) XXXVII = _______

(d)CD = _______