Content

Chapter Name of the Chapter Number

1. Numbers

2. Addition and Subtraction

3. Multiplication

4. Division

5. Factors and Multiples

6. Fractions

7. Measurement

8. Time

9. Money

10. Geometry

11 . Patterns and Symmetry

12. Perimeter and Area

13. Data Handling

Answers

Page Numbers

1-21

22-45

46-62

63-76

77-86

87-99

100-116

117-133

134-146

147-161

162-179

180-189

190-202

203-219

I s 0 g ~ s

~ -0 u6 t. 1 ~

1. Numbers

You Know

• reading and writing numbers up to 4-digit

• place value and face value of digits in a 4-digit number

• expanded and standard form of 4-digit numbers

• comparing and ordering 4-digit numbers

• formation of smallest and greatest 4-digit numbers using the given digits

You will Learn

• reading and writing numbers up to 5-digit and 6-digit numbers

• successor and predecessor

• place value and face value of digits

• expanded form of numbers

• comparing and ordering 5-digit and 6-digit numbers

• formation of smallest and greatest 5-digit and 6-dlgit numbers using the given digits

• rounding off numbers

• roman numerals

Kick Start

Pictorial representation

Number represented

1

111111111 ggg 99

Greatest 2-digit number

CJ +

1

I ■ • 10 100 1000

= ■ 100

Smallest 3-digit number

1-

■■■■■ ■■■II llllllllhg~ + 0

=

999 1

Greatest 3-digit number

( The greatest 4-digit number is 9999. J Let's revise the place value and face value of 4-digit numbers

I Th H T 0

9 4 1 l a .. •• ••

II 1000

Smallest 4-digit number

C The place value of 8 is 8 and its face value is also 8.

The place value of 1 is 10 and its face value is 1.

The place value of 4 is 400 and its face value is 4.

The place value of 9 is 9000 and its face value is 9.

The above number can be written in three ways as follows.

In figures In words

9418 Nine thousand four hundred eighteen

Let's Exercise

Exercise 1.1

1. Write the number names for the following.

a. 4725 b. 9872 c. 3947

2. Write the following numbers in figures.

a. Three thousand eight hundred forty

b. Nine thousand one hundred seventeen

c. One thousand twenty-four

d. Five thousand two hundred seventy-five

e. Eight thousand one

■ 2

In the expanded form

9000 + 400 + 10 + 8

d . 8216

'

3. Write the number represented on the abacus in figures and words.

a. b. c. d. I

I

I I

I I

I I I

◄ I I I I I I I

◄ I I I ~ I I I I I j I I j I ' . ' . "' " ' 0 "' " ' 0 "' " ' 0 "' "

4. Write the expanded form of the given numbers.

a. 2983 b. 7376 c. 4568 d. 1456

5. Write the following in the standard form.

a. 5000 + 400 + 60 + 9

C. 3000 + 700 + 3

b. 7000 + 400 + 70 + 9

d. 6000 + 9

' 0

6. Write the place value and face value of the underlined digit in the given numbers.

Numbers Place value Face value

: a. 106Z

~ j

b. 41Z4

c. Z802 I d. 3Z50 I

5-digit Numbers

We know that 9999 is the greatest 4-digit number.

Let's see what happens when we add 1 to it.

Th H • T 0

9 9 9 9

1 This is the Ten Thousands (TTh) place. 1 0 0 0 0

( 10000 is the smallest 5-digit number. ) The place value chart for numbers having 5 digits and more is divided into periods.

Periods helps us in reading and writing the large numbers.

In the Indian System of Numeration, the first period is ones period and the second period is thousands period that is to the left of ones period.

3 I

Periods ➔ Thousands

Places ➔ Ten Thousands Thousands Hundreds

(TTh) (Th) (H)

Ones

Tens

(T) Ones

(0)

( The ones period has three places - Ones, Tens and Hundreds. ]

The thousands period has two places - Thousands and Ten Thousands.

While writing the numbers in figures a comma ', • is used to separate the periods.

10000 can be represented in the place value table as follows:

TThTh HT 01 In figures it is written as 10,000.

1 0 0 0 0 In words it is written as Ten thousand.

Reading and Writing 5-digit Numbers

On adding 1 one to ten thousand, we get 10,001 .

It is written in words as Ten thousand one.

On adding 2 ones to ten thousand, we get 10,002.

It is written in words as Ten thousand two.

Let's count the numbers from 10,001 to 10,010.

Number Number name Number

10,001 Ten thousand one 10,006

10,002 Ten thousand two 10,007

10,003 Ten thousand three 10,008

10,004 Ten thousand four 10,009

10,005 Ten thousand five 10,010

On adding 1 hundred to ten thousand, we get 10,100.

It is written in words as Ten thousand one hundred.

On adding 1 thousand to ten thousand, we get 11 ,000.

It is written in words as Eleven thousand.

§ 1 Th

~ o

Number name

H

0

Ten thousand six

Ten thousand seven

Ten thousand eight

Ten thousand nine

Ten thousand ten

T

0

TTh Th 1 r o

H T 1 1 0

~ ·: On adding 2 thousands and 5 hundreds to ten thousand, we get 12,500.

~ Th H ' T IT 2 I 5 0

It is written in words as Twelve thousand five hundred.

■ 4

0 1

0 2

0 0

o ' 0

o ' 0

On adding 10 thousands to ten thousand, we get 20,000.

It is written in words as Twenty thousand.

TTh Th H

2 0 0 T 0 0 0

Thus, if we keep proceeding like this, we can form the remaining numbers up to 99,999.

( 99,999 is the greatest 5-digit number. J 6-digit Numbers

Let's see what happens when we add 1 to the greatest 5-digit number.

TTh Th H T 0 9 9 9 9 9

+ 1 This is the Lakhs (L) place. 1 0 0 0 0 0

( 100000 is the smallest 6-digit number. )

In addition to the ones period and thousands period 'Lakhs' period is used for reading and writing 6-digit number.

Periods ➔ Lakhs Thousands Ones

Places ➔ Lakhs Ten Thousands Thousands Hundreds Tens Ones

(L) (TTh) (Th) (H)

100000 can be represented in the place value table as follows:

L TTh Th H T 0

1 0 0 0 0 0

In figures it is written as 1,00,000.

In words it is written as One lakh.

( 9,99,999 is the greatest 6-digit number. )

Reading and Writing 6-digit Numbers

(T)

The number 7,63,512 can be represented in the place value table as follows:

T 0 --, In figures it is written as 7,63,512.

(0)

L TTh Th H

~ 6 3 5 1 2 In words it is written as Seven lakh sixty-three thousand five hundred twelve.

The number 2,87,409 can be represented in the place value table as follows:

L TTh Th H T 0 2 a -7---.--4__,...I -o--g

In figures it is written as 2,87,409.

In words it is written as Two lakh eighty-seven thousand four hundred nine.

s ■

Example 1 Write 1,37,261 in words.

Solution:

One lakh thirty-seven thousand two hundred sixty-one

Example 2 Write 'Two lakh fifty-four thousand nine hundred seventeen' in figures.

Solution:

2,54,917

Exercise 1.2

1. Fill in the missing numbers in the given sequence.

a. 11001. I I . I 1. 11004, I I . 11006, -=I =:!...1 . ~I =:!...I . =I =~ D DI ID D b. 20011 ,--, 20013,--.~~.--, 20017,--,20019

C. 40202, D , 40204, D , D, 40207, D D, 40210

D DD DD D d. ==---, 55062, -===-, -===-, 55065, ==---, -----=---, 55068, =='-

e. 185611.I I . I 1. 185674, I 1. I I. 185611, I 1, ... 1 _,L.

f. I 1 . 110963, I I, D. 110966, I I . 110968, D . 110910

g. I I . 238362, 238363, D . I 1, 238366, D . 238368, I I h. 425032, I I , 425034, D , I I, 425037, ! I, ! I , 425040

2. Put commas for the following numbers as per the Indian System of Numeration .

a. 89652 b. 70443 C. 217800 d. 319523 e. 920674

Write the number names for the following.

a. 90,001 b. 80,125 c. 1,41,987 d. 7,12,800 e. 2,00,125

Match the numbers with their names.

Numbers Number names

a. 38,366 i. Fifty-five thousand sixty-two

b. 70,163 ii. One lakh three thousand thirty-two

C. 55,062 iii. Twenty-five thousand eight hundred thirty-seven

d. 1,03,032 iv. Seventy thousand one hundred sixty-three

e. 25,837 V. Seven lakh forty thousand two hundred ten

f. 7,40,210 vi. Thirty-eight thousand three hundred sixty-six

■ s

5. Write the following in figures.

a. Ninety-five thousand three

c. One lakh two thousand sixty-two

e. Fifty thousand one hundred seventeen

b. Fifteen thousand one

d. Twenty one thousand thirty-seven

f. Three lakh fifty thousand four hundred one

6. Write the number represented on the abacus.

a. b. C.

TTllTlt HT 0 TTllTlt HT 0 L TTltTII HT 0

Successor and Predecessor

• The successor of a number is one more than the number. So we add 1 to the number to get its successor.

• The predecessor of a number is one less than the number. So we subtract 1 from the number to get its predecessor.

Write the successor of Example 1 2,48,529.

Solution:

2,48,529 + 1 = 2,48,530

Example 2 Write the predecessor of 8,70,461 .

Solution:

8,70,461 - 1 = 8,70,460

Therefore, the successor of 2,48,529 is Therefore, the predecessor of 8,70,461 is 2,48,530. 8, 70,460.

Exercise 1.3

1. Write the successor of each of the following numbers.

a. 10,301 b. 23,452 c. 6,40,000 d. 5,05,299

2. Write the predecessor of each of the following numbers.

a. 67,386 b. 80,921 c. 1, 12,059 d. 9,01 ,880

3. Fill in the blanks with the number that comes in between the given numbers.

a. 12,130; I I; 12,132 b. 78,598; I I; 78,600

C. 1,00, 160; I ! ; 1,00, 162 d. 5,96,455; ! !; 5,96,457

1 ■

- Place Value and Face Value of Digits

• The place value of a digit is given by its position in a number.

• The face value of a digit in a number is the value of the digit itself. It does not depend on the position of the digit.

The number 7, 16,342 can be represented in the place value table as follows:

Lakhs

7

Ten Thousands Thousands Hundreds

1 6 3

2 is at ones place, its place value is 2, its face value is 2.

4 is at tens place, its place value is 40, its face value is 4.

3 is at hundreds place, its place value is 300, its face value is 3.

Tens

4

6 is at thousands place, its place value is 6000, its face value is 6.

1 is at ten thousands place, its place value is 10,000, its face value is 1.

7 is at lakhs place, its place value is 7,00,000, its face value is 7.

Ones

2

Example 1 Write the place value and face value of each digit in the number 9,54,603.

Solution:

Digits 9 5

Place value 9,00,000 50,000

Face value 9 5

Expanded Form of Numbers

4

4000

4

6

600

6

0

0

0

3

3

3

[ The expanded form of a number expresses the number as the sum of the place ] values of its digits.

Example 2 Write the expanded form of 1,63,425.

Solution:

The expanded form of 1,63,425 can be represented as:

1,63,425 = 1 Lakh + 6 Ten thousands + 3 Thousands + 4 Hundreds + 2 Tens + 5 Ones

: (1 X 1,00,000) + (6 X 10,000) + (3 X 1000) + (4 X 100) + (2 X 10) + (5 X 1)

= 1,00,000 + 60,000 + 3000 + 400 + 20 + 5

■ a

Exercise 1.4

1. Write the place value and face value of the underlined digits.

a. 15,196 b. ~ .23,042 c. 3Q,602

e . .Q,61 ,201 f. 1,7§,323 g. 19,047

2. Write the expanded form of the following numbers.

a. 50,456 b. 4,55,678 c. 9,00,078

e. 1,21 ,354 f. 98,203 g. 7,10,102

Comparing Numbers

Comparison of two numbers with different number of digits

d. 59,1i8

h. 8,52,~63

d. 15,678

h. 9,43,174

If the two numbers being compared have different number of digits then the number with more number of digits is the greater number.

Example 1 Compare 64,981 and 1,72,324.

Solution:

L TTh Th

6 4

0 -· 1 ➔ 5 digits

1 7 2 3 2 4 ➔ 6 digits

Therefore, 1,72,324 > 64,981 .

Comparison of two numbers with same number of digits

If the two numbers being compared have same number of digits, then start comparing the leftmost digit of the two numbers.

Example 2 Compare 1,87,486 and 4,21 ,963.

Solution:

The number of digits in the both the numbers are same. Thus, compare the digits at the

lakhs place of the two numbers.

L TTh Th I H T 0

G) 8 7 4 8 6 ➔ 6 digits

@ 2 1 9 6 3 ➔ 6 digits

1<4

Therefore, 1,87,486 < 4,21 ,963.

9-

Example 3 Compare 6,29,714 and 6,01 ,922.

Solution:

The digits at the lakhs place of both the numbers are same. Thus, compare the digits at the ten thousands place of the two numbers.

L TTh Th H T 0

6 @ 9 7 1 4 ➔ 6 digits

6 @ 1 9 2 2 ➔ 6 digits

2>0

Therefore, 6,29,714 > 6,01 ,922.

Example 4 Compare 3,15,687 and 3,17,532.

Solution:

The digits at the lakhs and ten thousands place of both the numbers are same. Thus, compare the digits at the thousands place of the two numbers.

L TTh Th H T 0 3 1 @ 6 8 7 ➔ 6 digits

3 1 (J) 5 3 2 ➔ 6 digits

5<7

Therefore, 3,15,687 < 3,17,532.

Example 5 Compare 4,53,917 and 4,53,698.

Solution:

The digits at the lakhs, ten thousands and thousands place of both the numbers are

same. Thus, compare the digits at the hundreds place of the two numbers.

L TTh Th H

4 5 3 @ 4 5 3 @

9>6

T ol 1 7 ]➔ 6 digits

9 8 l➔ 6 digits

Therefore, 4 ,53,917 > 4,53,698.

Example 6 Compare 7,23,085 and 7,23,039.

Solution:

The digits at the lakhs, ten thousands, thousands and hundreds place of both the numbers are same. Thus, compare the digits at the tens place of the two numbers.

■ 10

L lnhl Th I H

7 2 3 0

7 2 3 0

T 0

@ 5 ➔ 6digits

@ 9 ➔ 6digits

8>3

Therefore, 7,23,085 > 7,23,039.

Example 7 Compare 5,90,131 and 5,90,134.

Solution:

The digits at the lakhs, ten thousands, thousands, hundreds and tens place of both the

numbers are same. Thus, compare the digits at the ones place of the two numbers.

L TTh Th H T 0

5 9 0 1 3 i G) ➔ 6 digits

5 fg 0 1 3 @ ➔ 6 digits

1<4

Therefore, 5,90, 131 < 5,90, 134.

Ordering Numbers

Ascending order: Arranging the given numbers in order from the smallest to the

greatest is called ascending order.

Example 8 Arrange the following numbers in ascending order.

12,450; 4, 70,532; 3,39,009; 12,936; 1, 10,080

Solution:

12,450 < 12,936 < 1, 10,080 < 3,39,009 < 4,70,532

Descending order: Arranging the given numbers in order from the greatest to the

smallest is called descending order.

Example 9 Arrange the following numbers in descending order.

15,621; 3,60,251; 5,32,203; 49,264; 7,05,911

Solution:

7,05,911 > 5,32,203 > 3,60,251 > 49,264 > 15,621

11 ■

Exercise 1.5

1. Compare the following numbers and put the correct sign '<', '>' or '=' in the given boxes.

a. 13,452 ID 113,217 b. 12,631 1□1 14,250 C. 99,999 11 119,99,999 d. 6,89,231 11 1190,712

e. 8,50.123 II 118,50.123 f . 2,16,342 11 112,16,088

2. Circle the greatest number from the following sets of numbers.

a. 10,001 ; 29,001 ; 11 ,451 ; 10,000

b. 67,235; 18,236; 1,46,920; 9,05,781

C. 2,49,231 ; 53,245; 1,92,460; 9,53,890

3. Circle the smallest number from the following sets of numbers.

a. 13,990; 13,521 ; 13,670; 13,099

b. 95,720; 78,115; 4,39,208; 7,09,161

C. 1, 12,300; 3,42,671 ; 60,789; 8,34,573

4. Arrange the following numbers in ascending order.

a. 85,800; 10,200; 20,000; 12,340; 41 ,009

b. 13,705; 19,804; 14,419; 17,390; 13,948

C. 3,38,743; 3,34,827; 3,35,246; 3,31 ,063; 3,12,415

d. 6,72,817; 6,73,817; 6,70,817; 6,71 ,817; 6,70,017

5. Arrange the following numbers in descending order.

a. 23,995; 29,995; 23,795; 22,395; 27,325

b. 31 ,750; 55,820; 33,420; 49,672; 15,672

C. 8,37,154; 8,39,154; 8,30,154; 8 ,33,154; 8,00,154

d. 2,50,467; 2,05,476; 2, 15,104; 2,31 ,532; 2,51,476

Formation of the Greatest and the Smallest Numbers

(: ■ 12

To form the greatest number, arrange the given digits in descending order.

To form the smallest number, arrange the given digits in ascending order. ]

Example 1 Form the greatest and the smallest 5-digit number using the digits 6, 1, 8, 4 and 2.

Solution:

Greatest 5-digit Number Smallest 5-digit Number

Arrange the digits in descending order. Arrange the digits in ascending order.

8 > 6 > 4 > 2>1 1 < 2<4<6 < 8

Therefore, the greatest 5-digit number is Therefore, the smallest 5-digit number is 86,421 . 12,468.

If one of the digits from the given digits is 'O' , then:

• the greatest number is formed by placing Oat the ones place.

• the smallest number is formed by placing O at the seconds place from the left.

Example 2 Form the greatest and the smallest 6-digit number using the digits 1, 7, 5, 3, 9 and 0.

Solution:

The greatest 6-digit number is 9,75,310. The smallest 5-digit number is 1,03,579.

Exercise 1.6

1. Form the greatest and the smallest 5-digit number using the given digits.

Numbers Greatest number Smallest number

a. 1, 5, 2, 3, 4 11 I b. 3, 4, 9, 0, 1 11 I C. 9,4, 6, 2, 8 11 I

2. Form the greatest and smallest 6-digit number using the given digits.

Numbers Greatest number Smallest number

a. 5, 4 . 1. 2. 6 , 1 ._ _______ __.I ... I ________ _

b. 2, 0, 9, 4, 8, 3 :::' ==============::::1:::1 ==============:::: C. 8, 1, 7, 5, 9, 0 I 1_1 _______ _

Rounding off Numbers

1,00,000 people watched the World Cup Cricket final at the stadium.

13 ■

The above sentence does not mean that exactly 1,00,000

people watch the match at the stadium. The number of people

might be more or less. 1,00,000 is the rounded off number. In

rounding off numbers, we approximate the numbers in

multiples of 10, 100 or 1000.

Rounding off Numbers to the Nearest 10

If the digit at the ones place of the given number is less than 5, we round off the number downwards by keeping the digit at the tens place digit as it is and replacing the digit at the ones place by 0.

Example 1 Round off 41 ,343 to the nearest 10.

Solution:

The digit at the ones place of the number is 3.

Since 3 < 5, we round off the number 41,343 as 41,340.

If the digit at the ones place of the given number is 5 or greater than 5, we round off the number upwards by increasing the digit at the tens place by 1 and repl.acing

the digit at the ones place by 0.

Example 2 Round off 78,688 to the nearest 10.

Solution:

The digit at the ones place of the number is 8.

Since 8 > 5, we round off the number 78,688 as 78,690.

Rounding off Numbers to the Nearest 100

If the digit at the tens place of the given number is less than 5, we round off the number downwards by keeping the digit at the hundreds place as it is and replacing the digits at the tens and ones place by 0.

Example· 3 Round off 41,343 to the nearest 100.

Solution:

The digit at the tens place of the number is 4.

Since 4 < 5, we round off the number 41 ,343 as 41 ,300.

■ 14

[

If the digit at the tens place of the given number is 5 or greater than 5, we round ] off the number upwards by increasing the digit at the hundreds place by 1 and replacing the digits at the tens and ones place by 0.

Example 4 Round off 78,688 to the nearest 100.

Solution:

The digit at the tens place of the number is 8.

Since 8 > 5, we round off the number 78,688 as 78,700.

Roundiing off Numbers to the Nearest 1000

[

If the digit at the hundreds place of the given number is less than 5, we round off ] the number downwards by keeping the digit at the thousands place as it is and replacing the digits at the hundreds, tens and ones place by 0.

Example 5 Round off 41,343 to the nearest 1000.

Solution:

The digit at the hundreds place of the number is 3.

Since 3 < 5, we round off the number 41 ,343 as 41 ,000.

If the digit at the hundreds place of the given number is 5 or greater than 5, we round off the number upwards by increasing the digit at the thousands place by 1 and replacing the digits at the hundreds, tens and ones place by 0.

Example 6 Round off 78,688 to the nearest 1000.

Solution:

The digit at the hundreds place of the number is 6.

Since 6 > 5, we round off the number 78,688 as 79,000.

Exercise 1.7

Round off the following numbers to the nearest 10, 100 and 1000.

a. 1567 b. 1068 c. 3421 d. 45,525

f. 91,766 g. 8, 12,432 h. 3, 16,894 i. 1,26,487

Roman Numerals

e. 17,667

j. 2,98,328

The Roman numeral system was used by the Romans in ancient Rome thousands of years ago. We can see Roman numerals on the dial of some clocks or wrist watches, chapter headings, etc.

15 ■

It is based on the seven letters of the English alphabet. The seven basic symbols used

in Roman numerals are I, V, X, L, C, D and M.

Roman Numerals

Hindu-Arabic Numerals 1

V

5

X

10

L

50

C

100

D

500

M

1000

The Roman numeral system does not have a symbol for zero. It does not have a place

value system.

Reading and Writing Roman Numerals

Roman numerals express numbers as sums and differences according to certain rules.

These rules are given below.

Rule 1: When a symbol is repeated, it means the value of each symbol is added. The

sum is equal to the number formed.

For example,

(i) II = 1 + 1 = 2 (ii) 111 = 1 + 1 + 1 = 3

(iii) xx = 10 + 10 = 20 (iv) XXX = 10 + 10 + 10 = 30

[: Symbol V cannot be repeated at all.

Symbols I and X cannot be repeated more than 3 times. ] Rule 2: When a symbol or symbols of smaller value are written after the symbol of

larger value, then their values are added to get the number.

For example,

(i) VIII = 5 + 1 + 1 + 1 = 8 (ii) XII = 10 + 1 + 1 = 12 (iii) XXV = 10 + 10 + 5 = 25

Rule 3: When a symbol of smaller value is written before a symbol of larger value, then

the value ,of the smaller symbol is subtracted from the value of the larger symbol.

For example,

(i) IV = 5 - 1 = 4 (ii) IX=10-1=9

[: ■ 16

Symbol I can be subtracted from V and X only.

Symbol V is never written on the left of X. ]

Roman Numerals up to 39

Hindu­Arabic

1

2

3

4

5

6

7

8

9

10

Roman

II

111

IV

V

VI

VII

VIII

IX

X

Exercise 1.8

Hindu­Arabic

11

12

13

14

15

16

17

18

19

20

Roman

XI

XII

XIII

XIV

xv

XVI

XVII

XVIII

XIX

xx

Hindu­Arabic

21

22

23

24

25

26

27

28

29

30

Roman

XXI

XXII

XXIII

XXIV

XXV

XXVI

XXVII

XXVIII

XXIX

XXX

1. Convert the Roman numerals to Hindu-Arabic numerals.

a. IX

e. XXXII

b. XV

f. 111

c. XXXVII

g. XIV

2. Convert the Hindu-Arabic numerals to Roman numerals.

a. 8 b. 4 C. 35 d. 26 e. 33 f . 19

Hindu­Arabic

31

32

33

34

35

36

37

38

39

d. VI

h. XXI

g. 39

3. Write the successor and predecessor of the following Roman numerals.

a. XI b. V c. XXXVI d. XX

Math Lab Activity

Objective: To reinforce the concept of rounding off numbers

Roman

XXXI

XXXII

XXXIII

XXXIV

XXXV

XXXVI

XXXVII

XXXVIII

XXXIX

h. 24

Materials required: black marker, one whiteboard to keep scores, 30 index cards

Procedure:

1. Draw 9 squares in a row on the ground.

2 . Label the squares as 100, 200, 300, 400, .............. ,900.

17 ■

3. On each index card write any one number from 100 to 900 such as 136, 510, 879, .... etc and prepare number cards.

4. Form 3 groups and select a group leader for each group.

5. Divide the number cards equally among 3 groups.

6. The group leaders of each group will distribute 1 number card to each member of his/her group.

7. Each group will take a turn at a time. The selected group member have to round off the number to the nearest hundreds place and then jump on the correct number square as quickly as possible.

8. For each correct answer the respective group will score 5 points.

t Math Challenge

Mickey arnd Kitty toss a coin to decide who among them will choose even and odd numbers respectively from the collection of numbers. Kitty chooses head and Mickey chooses tail. The coin is tossed and head appears as the ooin rests on the ground. So kitty wins the toss and she decides to choose even numbers. Help Kitty and Mickey collect even and odd numbers.

Colour the block with even number using blue colour and the blocks with odd number using yellow colour from the collection of numbers given below.

50,463 1 85,591 15,211 29,401

62,544 1 45,662 38,940 76,927

11 .199 I 82,086 93,988 68,757

93,554 1 28,396 44,703 71 ,131

Compare the numbers in each of the boxes above and answer the following questions.

a. Who has the greatest number? Write the number.

b. Who has the smallest number? Write the number.

c. How many numbers each of them have between 40,000 and 70,000?

d. How many numbers each of them have, such that at least one digit is repeated in that number?

■ 18

Math Around Me

Q\ Say No to Plastic!

~ What is the problem with plastic bags? - Our environment can't take more of

it. Plastic bags deface the landscape and destroy the environment. It remains in the environment for 1000 years and more.

1,60,000 plastic bags are used globally every second.

An average family uses

approximately 60 plastic bags in a month.

The number of plastic

bags manufactured yearly if placed side by

side, they can encircle the world 7 times.

1. 1,60,000 plastic bags are used globally every second. (Write the expanded form of the number)

2. Approximately 40,000 plastic checkout bags were dumped in landfills every hour in New Zealand (Write the number in words)

f:I Its time to go back to cloth bags and paper bags like before. ~ eco-friendly bags and stop asking for plastic bags at the shops.

Being light weight and aerodynamic, even if disposed properly,

they get carried away with the wind to the different places harming

the animals and birds.

In the oceans, plastic bags have killed at least 1,00,000 birds,

whales, seals and turtles every year. The bags look like jellyfish

in the water. The turtles and other animals who mistake them for

jellyfish and feed on them get killed.

Use

3. In the oceans, plastic bags have killed at least 1,00,000 birds, whales, seals

and turtles every year. (Write the numeral in words in the Indian System of

Numeration and rewrite the sentence.)

Countries like Canada, South Africa, Singapore have already banned plastic bags.

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Let's Summarize

Smallall 5-digll numbe, • 10.000

Gt.-. 5-dlglt number• 99,999

Place ~ue ol • digil depeods on Ila l)0Sillon In lhe number.

F110e value of a digit in a number II Iha Qlult of lhe digit ll:Mlf.

.,. __ ol. number. one more than Ille number.

Prede, •-of• number II ti-----11111111 one lea thin 1tw number.

In roundrlg oft runberl, we appro1tlmale lhe numbers in moA,,ples of 10, 100 °' 1000.

Revision Exercise

1. Write the following numbers in words.

a. 56,486

d. 1,30,947

b. 12,385

e. 6,18,973

~d41d fonn ol • number . .. l'-ffl ol lhe plac:e value alb digits

Smllllnl &-digit number• 1,00,000

GrNlell 6-digil nunw = e.99.999

Indian SytMm of Numeration: Ones period· Ones, T-and Hundrads

Thousands period - Thol-,cls and Ten IIOIMMdl lalths period • Lalths

Aloendlng ordet: Se! of numbe<s arrangad from smalnt 10 Q1'N1Nt

~-Selol ~ arranged from gr..-i ID smellast

Seven laaara UNd lo rep,-,c numbert In Roman num.a · I. V, X. L. C. 0 and M

C. 80,064

f. 7,39,076

2. Write the following numbers in figures. Put commas as per the Indian System of Numeration.

a. Thirty-nine thousand six hundred five

b. Nine lakh one thousand forty-one

c. Fifty two thousand eighty

d. Four lakh six thousand seven hundred nine

3. Write the successor and predecessor of the following numbers.

a. 48,530 b. 9,28,376 C. 3,05,694 d. 76,341

4. Write the place value of the underlined digit in each of the following numbers.

a. 2~792

d. 1, 1Q,937

b. Z, 18,435

e. 45,6,a9

5. Write the expanded form of the following numbers.

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a. 34,785

d. 95,329

b. 8,67,196

e. 17,964

C. 6,40,59~

f. 99,J22

c. 5,61,483

f. 7,13,249

6. Round off the following numbers to the nearest 10, 100 and 1000.

Number Round off the number to the

Nearest 10 Nearest 100 Nearest 1000

a. 67,458

b. 20,398 ::===========:::: ::===========:::: ;:===========::: C. 8,96,948

d. 1,23,349

7. Compare the following numbers and put the correct symbol '< ' , '>' or ·=· in the boxes.

a. 13,452 D 64,926 b. 48,823 D 48,629

C. 39,846 D 39,846 d. 17,964 D 9,58,570

e. 1,84,769 D 1,84,796 f. 78,568 D 1,37,203

8. Arrange the following sets of numbers in ascending order.

a. 97,824; 95,103; 97,564; 95,781

b. 3,40,785; 3,70,236; 3,40,764; 4,03,686

9. Arrange the following sets of numbers in descending order.

a. 59,246; 57,468; 59,763; 59,756

b. 2,03,975; 2,03, 787; 2, 17,548; 2, 13,469

10. Complete the following table.

Roman numerals Hindu-Arabic numerals

a. 22

b. XVI

C. 35

d. XXVII I e. I 18

f. XIX I g. 31

Weblinks

http://thinkmath.edc.org/resource/who-am-i-puzzles

https://www.iknowit.com/lessons/b-rounding-nearest-ten-99.html

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As on 26.03.2019

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