CHAPTER 2
Question: 1
Look at the picture and explain how Birbal made Akbar’s line shorter.
Answer: Birbal drew a longer line than the line drawn by the Akbar.
Question: 2
Make her right arm 1 cm longer than the left arm.
Answer:
Question: 3
Draw a cup 1 cm shorter than this cup.
Answer: The cup drawn is 1 cm shorter than the given cup
Question: 4
Draw a broom half as long as this broom.
Answer: A broom half of the size of broom given in figure is drawn below
Question: 5
Draw another hair of double the length.
Answer: Hair of double length is drawn below
NCERT book Page No: 15
How Tall Have You Grown?
Question: 6
Do you remember that in Class 3 you measured your height?
Answer: Yes, I measured my height in Class 3
Question: 7
Do you think you have grown taller?
Answer: Yes, I have grown taller
Question: 8
How much?
Answer: About 5 cm
Question: 9
Have your friends also grown taller?
Answer: Yes, most of them have grown taller
Question: 10
Jhumpa once read a list of the tallest people in the world. One of them was 272 cm tall! That is just double of Jhumpa’s height. How tall is Jhumpa? __________ cm.
Answer: Height of the tallest person = 272 cm
Which is double than Jhumpa’s height
So,
272 ÷ 2 = 136 cm
Hence, Jhumpa’s height is 136 cm
Question: 11
Could that person pass through the door of your classroom without bending?
Answer: Since, the door of the classroom is 230 cm high. So, the person cannot pass through it without bending.
Question: 12
Will his head touch the roof of your house if he stands straight?
Answer: Yes, because the height of my classroom is 310 cm
The Long and Short of Your Family!
Question: 13
Who is the tallest in your family?
Answer: My father is the tallest in my family. His height is 174 cm
Question: 14
Who is the shortest in your family?
Answer: My brother is the shortest in my family. His height is 93 cm
Question: 15
What is the difference between their heights?
Answer: The difference between their heights is 81 cm
NCERT book Page No: 16
Race
Question: 16
(a) How far is Rehana from Arundhati?
Answer: The distance of Rehana from Arundhati is 3 metres.
(b) How far ahead is Rehana from Konkana and Uma?
Answer: Rehana is 6 metres ahead from Konkana and Uma
(c) How far are Konkana and Uma from the finishing line?
Answer: Konkana and Uma are 15 metres far from the finishing line
Question: 17
Have you heard about a 1500 m or 3000 m race? (You remember that 1000 metres make 1 kilometre and 500 metres make half a kilometre.)
(a) In a 1500 metres race people run ______ km
Answer: In a 1500 metres race people run one and half km
(b) In a 3000 metres race people run _______ km
Answer: In a 3000 metres race people run 3 km
NCERT book Page No: 17
Question: 18
Have you heard about marathon races in which people have to run about 40 kilometres? People run marathons on roads because the track of a stadium is only 400 metres.
(a) 10 rounds of a stadium track = ________ km
Answer: 10 rounds of a stadium track = 400 metres × 10
= 4000 metres
= 400 ÷ 1000
= 4 km
So, 10 rounds of a stadium track = 4 km
(b) So, if you run a marathon on a stadium track, you will have to complete rounds!
Answer: The number of rounds to be completed
= (40 × 100) ÷ 100
= 4000 ÷ 100
= 10
Hence, you have to complete 10 rounds on a stadium track
Question: 19
Dhanu has the longest jump of 3 metres 40 cm. Gurjeet is second. His jump is 20 cm less than Dhanu’s. Gopi comes third. His jump is only 5 cm less than Gurjeet’s jump.
How long are Gurjeet’s and Gopi’s jumps?
Answer: Gurjeet’s jumps = Dhanu’s jump – 20 cm
= 3 metres 40 cm – 20 cm
= 3 metres 20 cm
Therefore, Gurjeet’s jump is 3 metres 20 cm
Gopi’s jump = Gurjeet’s jumps – 5 cm
= 3 metres 20 cm – 5 cm
= 3 metres 15 cm
Therefore, Gopi’s jump is 3 metres 15 cm
Question: 20
Find out from the table
1. How many centimetres more should Chandra Pal jump to equal the Men’s World Record for high jump?
Answer: We know that,
1 m = 100 cm
Given
Men’s world record for high jump = 2 m 45 cm
= 2 × 100 + 45 cm
= 200 cm + 45 cm
= 245 cm
High jump record of Chandra Pal = 2 m 17 cm
= 2 × 100 + 17 cm
= 200 cm + 17 cm
= 217 cm
Now, subtract 217 from 245, we get
245 – 217 = 28 cm
Hence, to equal the men’s world record for high jump, Chandra Pal need to jump 28 cm more.
2. How many centimetres higher should Bobby A jump to reach 2 metres?
Remember that 1 m = 100 cm
Half metre =?
Answer: Bobby A, high jump record = 1 m 91 cm
= 1 × 100 + 91 cm
= 191 cm
Required centimetres to reach is 2m
So,
= 2 × 100
= 200 cm
Thus,
200 – 191 = 9 cm
Therefore, Bobby A should jump 9 cm higher to reach 2 metres
3. Galina’s long jump is nearly
(a) 7 metres
(b) 7 and a half metres
(c) 8 metres
Answer: Galina’s long jump record is 7 m 52 cm
Hence, it is nearly 7 and half metres,
Therefore option (b) is correct
4. Look at the Women’s World Records. What is the difference between the longest jump and the highest jump?
Answer: Women’s World record for high jump = 2 m 9 cm
Women’s World record for long jump = 7 m 52 cm
So, difference between them is
= 7 m 52 cm – 2 m 9 cm
= 5 m 43 cm
5. If Mike P, could jump _______ centimetres longer, his jump would be full 9 metres.
Answer: Mike P long jump record = 8 m 95 cm
To reach 9 metres = 9 m – 8 m 95 cm
= 5 cm
Therefore, if Mike P jump 5 cm longer, his jump would be full 9 metres
6. Whose high jump is very close to two and half metres?
(a) Stefka K.
(b) Chandra Pal
(c) Javier S.
(d) Bobby A.
Answer: Javier S high jump is 2 m 45 cm. So, his jump is very close to two and half metres.
NCERT book Page No: 19
Question: 21
* How many rounds of the park must Devi Prasad run to complete 2 km?
Answer: We know that,
1 km = 1000 m
So,
2 km = 2000 m
Hence, to complete 2000 m, Devi Prasad must complete
= 2000 m ÷ 400 m
= 5 rounds
Therefore, Devi Prasad has to complete 5 rounds of the park
* One day the weather was very good and a cool breeze was blowing. He felt so good that he kept jogging till he got tired after 8 rounds. That day he ran _______ km and _________ metres!
Answer: Distance covered to complete one round of the park = 400 m
So, distance covered by Devi Prasad to complete 8 rounds of the park = 400 m × 8
= 3200 m
We know,
1000 m = 1 km
Therefore, 3200 m = 3000 m + 200 m
3000 m = 3000 ÷ 1000
= 3 km 200 m
Hence, Devi Prasad ran 3 km 200 m to complete 8 rounds of the park
NCERT book Page No: 20
From Kozhikode to Thalassery
Subodh is going to Kozhikode which is 24 kilometres (km) away. Manjani is going to Thalassery which is 46 km away in the opposite direction.
Question: 22
How far is Kozhikode from Thalassery? ________
Answer: Kozhikode distance from Thalassery
= Kozhikode distance + Thalassery distance
= 24 km + 46 km
= 70 km
Question: 23
*How much does Momun walk every day to reach school? ________
Answer: Total distance of school from Momun home = 400 m + 150 m + 350 m + 40 m
= 940 m
Therefore, Momun has to walk 940 m every day to reach school
* Is it more than 1 km? ________
Answer: Since, 940 m is less than 1000 m
Therefore, it is not more than 1 km
Question: 24
Find out how far your friends live from school and fill the table. Write in metres or kilometres.
Answer: Following are the list of distance of school from their home
| Friends Name | Distance of home from school |
| Sohail | 500 m |
| Amit | 2 km 100 m |
| Alok | 1 km 400 m |
| Sanjeev | 1 km 100 m |
| Rohit | 5 km 400 m |
| Rahul | 2 km 400 m |
* Who among you lives nearest to the school?
Answer: A person who lives nearest to the school is Sohail
* Who lives farthest from the school?
Answer: A person who lives farthest from the school is Rohit
* How many children live less than 1 km away from your school?
Answer: Me and Sohail. That means total two children lives less than 1 km away from school
* Is there anyone who lives more than 5 km away from the school?
Answer: Yes, Rohit lives more than 5 km away from the school
* How do they come to school?
Answer: They come to the school by school bus.
Guess and Find Out
Question: 25
How long is the thread in a reel?
Answer: The length of thread can be measured depending on the thickness of reel.
It may be 60 metres, 90 metres, 100 metres or 400 metres or more
Question: 26
How long is the string of a kite reel? Can it be more than a kilometre long?
Answer: A kite reel can be more than a kilometre long. It may be 500 metres, 900 metres, 1000 metres long.
Question: 27
If a handkerchief is made out of a single thread, how long would that thread be?
Answer: The length of thread may be about 4000 metres, if a handkerchief is made out of a single thread.
NCERT book Page No: 22
Try to find out:
Question: 28
Which is the highest building that you have seen? About how many rooms high was it?
Answer: The highest building that I saw is Qutub Minar. It is about 25 rooms high
Question: 29
How high can a kite go? Can it go higher than the Qutub Minar?
Answer: Yes, a kite can go higher than the Qutub Minar. It may go about 100 metres high.
Question: 30
How high can a plane fly? Can it fly higher than Mount Everest which is about 9 km high?
Answer: A plane can fly more than 10000 metres high. Yes, it can fly higher than the Mount Everest which is about 9 km high.
Class 4 maths chapter 2,
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