KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic

   

Students can Download Maths Chapter 3 Mental Arithmetic Questions and Answers, Summary, Notes Pdf, KSEEB Solutions for Class 5 Maths helps you to revise the complete Karnataka State Board Syllabus and score more marks in your examinations.

Karnataka State Syllabus Class 5 Maths Chapter 3 Mental Arithmetic

KSEEB Class 5 Maths Mental Arithmetic Revision Exercise

I. Round off each of the following numbers to nearest thousands place:

1. 7,547

7,547 lie between 7000 and 8000
Replace by zero
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 1

2. 3,469
3,469 lie between 2000 and 3000
Replace by zero
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 2

KSEEB Solutions

3. 15,238
15,038
Replace by zero
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 3

4. 32,658
32,658
Replace by zero
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 4

II. Round off each of the following numbers to nearest ten thousands place:

1. 26,674
26,674
Replace to zero
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 5

2. 32,464
32,464
Replace to zero
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 6

3. 46,379
46,379
Replace to zero
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 7

4. 53,668
53,668
Replace to zero
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 8

III. Estimate sum of the following by rounding off to nearest thousands place:

1. 42,125 + 35,637
42,125 is rounded off to nearest thousand – 42,000
35,637 is rounded off to nearest thousand – 36,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 9
Estimate sum is 78,000
Verification by actual addition – 42125
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 10

KSEEB Solutions

2. 54,837 + 41,354
54,837 is rounded off to nearest thousand – 55,000
41,354 is rounded offto nearest thousand – 41,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 11
Estimate sum is 96,000
Verification by actual addition
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 12

3. 33,231 + 20,097
33,321 is rounded off to nearest thousand – 33,000
20,097 is rounded off to nearest thousand – 20,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 13
Estimate sum is 53,000
Verification by actual addition
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 14

4. 47,463 + 41,541
47,463 is rounded off to nearest thousand – 47,000
41,541 is rounded off to nearest thousand – 42,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 15
Estimate sum is 89,000
Verification by actual addition
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 16

IV. Estimate the sum of the following by rounding off to nearest ten thousands place:

1. 56,256 + 24,872
56,256 is rounded off to nearest ten thousand – 55,000
24,872 is rounded off to nearest ten thousand – 25,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 17
Estimate sum is 80,000
Verification by actual addition
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 18

KSEEB Solutions

2. 47,671 + 28,745
47,671 is rounded off to nearest ten thousand – 50,000
28,745 is rounded off to nearest ten thousand – 30,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 19
Estimate sum is 80,000
Verification by actual addition
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 20

3. 32,184 + 45,138
32,184 is rounded off to nearest ten thousand – 30,000
45,138 is rounded off to nearest ten thousand – 50,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 21
Estimate, sum is 80,000
Verification by actual addition
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 22

4. 15,025 + 40,165
15,025 is rounded off to nearest ten thousand – 20,000
40,165 is rounded off to nearest ten thousand – 40,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 23
Estimate sum is 60,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 24

Detailed Steps to Round to Nearest Hundredth by Hand ·

V. Estimate the difference of the following by rounding off to nearest thousands place:

1. 65,487 – 46,502
65,487 is rounded off to nearest ten thousand – 64,000
46,502 is rounded off to nearest ten thousand – 46,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 25
Estimate sum is 18,000
Verification by actual substruction
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 26

KSEEB Solutions

2. 45,630 – 32,148
45,630 is rounded off to nearest ten thousand – 44,000
32,148 is rounded off to nearest ten thousand – 30,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 27
Estimate sum is 14,000
Verification by actual substruction
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 28

3. 57,146 – 25,472
57,146 is rounded off to nearest ten thousand – 56,000
25,472 is rounded off to nearest ten thousand – 24,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 29
Estimate sum is 32,000
Verification by actual substraction
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 30

4. 60,046 – 15,247
60,046 is rounded off to nearest ten thousand – 60,000
15,247 is rounded off to nearest ten thousand – 15,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 31
Estimate sum is 45,000
Verification by actual substraction
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 32

VI. Estimate the difference of thefolhming hy rounding off to nearest ten thousands place:

1. 51,689 – 34,685
51,689 is rounded off to nearest ten thousand – 50,000
34,685 is rounded off to nearest ten thousand – 30,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 33
Estimate sum is 20,000
Verification by actual substraction
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 34

2. 86,853 – 47,829
86,853 is rounded off to nearest ten thousand – 85,000
47,829 is rounded off to nearest ten thousand – 45,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 35
Estimate difference is 40,000
Verification by actual substraction
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 36

KSEEB Solutions

3. 80,808 – 55,055
80,808 is rounded off to nearest ten thousand – 80,000
55,055 is rounded off to nearest ten thousand – 50,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 37
Estimate difference is 30,000
Verification by actual substractiori
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 38

4. 77,777 – 44,444
77,777 is rounded off to nearest ten thousand – 70,000
44,444 is rounded off to nearest ten thousand – 40,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 39
Estimate difference is 30,000
Verification by actual substraction
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 40

VII. Estimate the product of each of the following hy rounding off to its highest place:

1. 428 × 54
428 is rounded off to nearest hundred as 400
54 is rounded off to nearest ten as 50
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 41
Estimate product is 20,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 42

2. 878 × 46
876 is rounded off to nearest hundred as 900
46 is rounded off to nearest ten as 50
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 43
Verification by actual multiplication

Verification by actual multiplication
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 44

3. 5,476 × 11
5,476 is rounded off to nearest hundred as 5000
11 is rounded off to nearest ten as 10
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 45
Verification by actual multiplication

Verification by actual multiplication
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 46

KSEEB Solutions

4. 2,645 × 18
2,645 is rounded off to nearest hundred as 3000
18 is rounded off to nearest ten as 20
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 47
Verification by actual multiplication

Verification by actual multiplication
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 48

VIII. Estimate the quotient of each of the following hy rounding off to its highest place.

1. 398 ÷ 82
398 is rounded off to nearest hundred aS 400
82 is rounded off to nearest ten as ÷ 80
Estimate quotient \(\frac{800}{40}\) = 5

2. 786 ÷ 22
786 is rounded off to nearest hundred as 800
22 is rounded off to nearest ten as ÷ 20
Estimate quotient \(\frac{800}{20}\) = 40

3. 3,265 ÷ 58
3,265 is rounded off to nearest hundred as 3000
58 is rounded off to nearest ten as ÷ 60
Estimate quotient \(\frac{3000}{60}\) = 50

4. 7,687 ÷ 43
7,687 is rounded off to nearest hundred as 8000
43 is rounded off to nearest ten as ÷ 40
Estimate quotient \(\frac{8000}{40}\) = 200

IX. Solve the following problems.

Question 1.
A garment company stitched 16,783 shirts and 12,438 pants in a month. Estimate the total number of dresses stitched to the nearest ten thousands place.
Answer:
A garment company stitched shirts – 16,783
A garment company stitched pants – 12,438.
(To the nearest ten thousand place) – 20,000
(To the nearest ten thousand place) – 10,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 49
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 50

Question 2.
A news paper agent sells 36,721 papers in first month and 24,172 papers in sec¬ond month. Estimate the decrease in sale of the newspaper in second month to the nearest ten thousands place.
Answer:
In first month a news paper agents sells – 36,721
In Second month a news paper agents sells – 24,172
(To the nearest ten thousand place)
first month – 40,000
Second month – 20,000
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 51
The estimated substraction of sale of the newspaper 20,000

KSEEB Solutions

Question 3.
A train can cover 225 km in one hour. Estimate the distance covered in a day to the highest place.
Answer:
A train can cover 225 Km in 1 hour
The distance covered in a day = 24 hours
(To the highest place) 200
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 52

Question 4.
A carpenter earned Rs. 18,634 during the month of November and Rs. 32,645 in December. Estimate how much more he earned in December to the nearest ten thousands place.
Answer:
A carpet earned in november – 18,634
A carpet earned in december – 32,645
(To the nearest ten thousand place)
KSEEB Solutions for Class 5 Maths Chapter 3 Mental Arithmetic 53

KSEEB Solutions

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