NCERT Solutions for Class 5 Maths Chapter 10 Tenths And Hundredths
NCERT Textbook Page 134
1.What was the length of the smallest pencil you have used?
Ans. The length of the smallest pencil which I used was 5 cm.
2.How long is this pencil? Guess ————cm.
Measure it using a scale. How good is your guess?
Ans.I guess it is 3.5 cm long.
On measuring, it turned out to be 3.6 cm long. So, I made a good guess.
NCERT Textbook Page 135
1.What is the length of this pencil?————- mm. What is its length in centimetre?
Ans. The length of the pencil is 6 mm. Its length in centimetre is 0.6 cm.
2.Have you seen frogs? Where? How many different types of frogs have you seen? Are all the frogs of the same length? Here are two interesting examples.
Ans. Yes, I have seen frogs. I have seen them in puddles of water. I have seen two types of frogs; one of them looks green and another looks pale brown. Different frogs are of different lengths.
1.This kind of frog is among the smallest in the world. Its length is only 0.9 cm! >- Guess how many such frogs can sit on your little finger!
Ans. I think four of them can sit on my little finger.
But this is among the biggest frogs. It is as long as 30.5 cm.
1.What does 0.9 cm mean? It is the same as——— millimetres. We can also say this is nine-tenths of a cm. Right?
Ans. 0. 9 cm = 9 mm
Yes, it is nine-tenth of a cm.
2.So 30.5 cm is the same as———-cm and———– millimetres.
Ans. 30.5 cm = 30 cm and 5 millimeter.
3.About how many of the big frogs will fit on the 1 m scale?
Ans. 1 m = 100 cm
If 100 is divided by 30 then we get 3 as quotient and 10 as remainder.
So, it can be said that 3 to 4 such frogs can sit on a 1m scale.
4.If they sit in a straight line about how many of the small frogs will cover 1 m?
Ans. 1 m = 100 cm = 1000 mm
If 1000 is divided by 9 mm then we get 111 as quotient and 1 as remainder. So, it can be said that 111 small frogs will cover 1 m.
NCERT Textbook Pages 135-136
1.Length of the nail – 2 cm and……….mm or 2. – cm.
Ans. 2 cm and 9 mm or 2.9 cm.
Ans.The length of this lady’s finger (bhindi) is 8 cm and 3 mm. We can also write it as 8.3 cm.
NCERT Textbook Page 137
Guess, Draw and Measure
1.Guess the lengths to draw these things. Ask your friend to draw the same. After you make the drawing, use a scale to measure the length. Whose drawing showed a better guess?
NCERT Textbook Page 137
Our Eyes Get Confused?
1.Which line is longer? A or B. Measure each line and write how long it is in centimetres. How good is your guess?
Ans. I think line B is longer than A.
A = 4.6 cm B = 4.6 cm .
2.Which line is longer? C or D? Measure each line. How good is your guess?
Ans. Line C seems to be longer.
On measuring both lines are equal.
Line C = 3.2 cm Line D = 3.2 cm
NCERT Textbook Page 138
Whose Tail is the Longest?
1.Guess whose tail is the longest. Now measure the tails. How good is your guess?
Ans. I think the tail of the monkey is the longest. Correct measurements are as follows:
Hint: Use thread to measure the tails of animals given in the figure.
The Longest Rupee Notes?
1.What is the length of a 100 rupee note? Guess.
Now measure it using a scale.
Ans. I guess that the 100 rupee note is 16 cm long. On measuring I found it 15.5 cm long.
2.Now guess the length and width of many other things. Measure and find the difference between your measure and your guess.
NCERT Textbook Page 139
At the Market
1.How many paise does a matchbox cost?
Ans. 50 paise.
2.How many matchboxes can be got for Rs 2.50?
3.How many rupees does the soap cost?
4.Arun wanted to buy a soap. He has a five-rupee coin, 2 one-rupee coins and 4 half-rupee coins. Write in rupees what money he will get back?
Ans. Total money with Arun
= (Rs 5 x 1) + (Re. 1 x 2) + (4 x 0.5)
=5+2+2 = Rs 9
Cost of one soap =Rs 8.75
Arun will get back =Rs 9 — Rs 8.75
= (900 – 875) paise
= 25 paise = Re. 0.25
(a) An egg costs two and a half rupees. How much will one and a half dozen cost?
Ans. Cost of an egg = Rs 2.50
One and a half dozen eggs = 12 + 6 = 18 eggs Cost of 18 eggs = 18 x 2.50
= 18 x 2 + 18 x 0.50 = 36 + 9 = Rs45
Money left = Rs60 — Rs45 = Rs15
5.The price of two pens is Rs 13. Can she buy two pens?
Ans. Yes, she can buy two pens with Rs 13.
NCERT Textbook Page 140
Practice Time—Match These
1.Match each yellow box with one green and one pink box.
1.What part of this sheet is coloured blue?
Ans. 1/10 part is blue.
2.What part of the sheet is green?
3.Which colour covers 0.2 of the sheet?
[Hint: Oh, the blue strip is 0.1 of the sheet!]
4.Now look at the second sheet. Each strip is divided into 10. equal boxes. How many boxes are there in all?
Ans. 10 x 10 = 100.
(а)Is each box 1/100 part of the sheet?
(b)How many blue boxes are there?
Ans. 10 blue boxes
(c) Is blue equal to 10/100 of the sheet? We saw that blue is also equal to 1/10 of the sheet. We wrote it as 0.1 of the sheet.
10/100 = 1/10 = 0.1
5.Can we say 10/100 = 1/10 = 0.10 = 0.1?
6.Think: Can we write 10 paise as 0.1 of a rupee?
Ans. Yes, we can write 10 paise as 0.1 of a rupee.
7.How many boxes are red? What part of the sheet is this?
Ans. 15 boxes. This is 15/100 part.
8.Can we also write it as 0.15 of the sheet?
(Hint: Remember we wrote 99 paise as 0.99 rupee!)
9.Now 3/100 of the sheet is black. We can say 0. sheet is black.
10.How many white boxes are there in the sheet?
11.What part of the second sheet is white?
12.Make your designs.
Make a nice design by colouring 0.45 part of this square red.
13.Use four colours. Each colour should cover 0.05 of this square.
NCERT Textbook Page 141
The school at Malappuram has its sports day.
The first five children in the Long Jump are:
Teena: 3.50 m Meena: 4.05 m Rehana: 4.50 m Anu: 3.05 m Amina: 3.35 m
Teena jumped 3.50 m which is 3 m and 50 cm.
1.But how far did Anu jump?————— m and—————cm
Ans. 3 m and 5 cm.
2.Who is the winner in the long jump?
3.Write the names of the I, II and III winners on this stand.
Do you remember that 1 metre = 100 centimetre? So one centimetre is 1/100 of a metre.
We also write 1 cm as 0.01m
NCERT Textbook Page 142
Write in Metres
3 metre 45 centimetre = 3.45m
99 centimetre = 0.99m
1 metre and 5 centimetre = 1.05m
(a)How Big Can You Get
After breathing out 1.52 m On taking a deep breath 1.82 m Difference in size = 1.82 – 1.52 = 0.30 m Do this for yourself and find the difference.
(b)What is Dinesh’s height in metres?
NCERT Textbook Page 143
Money from different countries
1.Have you seen any notes or coins used in any other country?
Ans. Yes, I have seen the notes and coins of the United Kingdom.
2.Shivam Bank has a chart to show us how many Indian rupees we can get when we change the money of different countries.
(This is the rate on 15-2-2008)
(a)The money of which country will cost the most in Indian Rupees?
Ans. The money of England will cost the most in Indian Rupees.
(b)Mithun’s uncle in America had sent him 10 USA dollars as a gift. Mithun used 350 rupees for a school trip. How much money was left with him?
Ans. Money received by Mithun = 10 USA Dollar 1 USA Dollar = 39.70
Hence, money received by Mithun = 10 x 39.70
= 10 x 39 + 10 x 0.70 = 390 + 7 = 397 rupees
Money spent on school trip = Rs350
Money left with him = Rs397 — Rs350 = Rs47
(c)Majeed’s father is working in Saudi Arabia. He gets 1000 Saudi Riyal as salary. Arun’s father who is working in Sri Lanka gets 2000 Sri Lankan Rupees. Who gets more Indian Rupees as salary?
Ans. Majeed’s Father’s salary = 1000 Saudi Riyal
= 1000 x ? 10.52 = 1000 x 10 + 1000 x 0.52
= 10000 + 520 = 10520 Rupees
Arun’s father’s salary = 2000 Sri Lankan Rupees
= 2000 x Rs0.37 = 2000 x 37 paise = 74000 paise
= 740 Rupees
Hence, Majeed’s father gets more Indian rupees.
(d)Leena’s aunty brought a present for her from China. It cost 30 Yuan. Find what it costs in Indian rupees.
Ans. 1 Yuan = Rs 5.50
So, 30 Yuan = 30 x 5.50
= 30 x 5 + 30 x 0.50 = 150 + 15 = 165 Rupees
(e)Astha wants some Hong Kong Dollars and Won.
(i)How many Won can she change for Rs 4? For Rs 400?
(ii)How many Hong Kong Dollars can she change for Rs 508?
Ans. (i) 1 Won = Re. 0.04
Hence, 100 Won = 4 (Multiply on both sides by 100)
Hence, Astha gets 100 Won for Rs4
And for Rs400 she gets:
100 x 100 = 10000 Won
(ii) 1HK Dollar = Rs 5.10 Hence, Rs 508 = 508 + 5.10
= 99.61 HK Dollar
3.Kiran went shopping with Rs 200. Look at the bill. The shopkeeper forgot to put the point correctly in the prices. Put the point in the correct place and find out the total amount of the bill.
Ans. The correct bill is as follows:
NCERT Textbook Page 145
Which City Is Cool?
The temperature in each city was noted at 3 p.m. on 16 January 2008.
1.Which place had the highest temperature at 3 p.m.? Which place is the coolest at that time?
Ans. Mumbai had the highest temperature.
Srinagar is the coolest place at that time.
2.How much higher is the temperature in Mumbai from that in Srinagar?
Ans. (35.1-8.1)°C = 27.0°C
3.How many degrees will the temperature need to rise for it to reach 40°C in Thiruvanantha- puram?
Ans. 40°C – 33.5°C = 6.5°C
4.How much lower is tha temperature in Kolkata from that in Chennai?
Ans. 29.9°C – 26.6°C = 3.3°C
5.The temperature in these cities was also noted at 3 a m. on the same day. Look at the table and answer the questions.
Which place had the lowest temperature at 3 a.m.? Imagine yourself to be there and describe how it would feel.
The temperature is 1.3°C means it is very cold and the water in pipes froze into ice. We will have to wear woolen cloths and sit near fire.
(b)What is the difference between the temperatures at 3 p.m. and 3 a.m. in Chennai? In Bhopal?
Temperature at 3 p.m. = 29.9°C Temperature at 3 a.m. = 21.1°C Difference = 29.9°C – 21.1°C = 8.8°C
Temperature at 3 p.m. = 25.9°C Temperature at 3 a.m. = 9.8°C