**NCERT Solutions for Class 4 Mathematics Unit-9 Halves And Quarters**

**NCERT Textbook Page 95**

**Half-Half**

**1. If the cats ask you to divide the chapati equally, how will you divide it?**

**Ans.** I will fold the chapati in two halves, as a circle was folded in previous chapter to locate the centre.

And then I will tear them apart from the creased line.

Half of Half

**2. If two more cats come for food, how will you divide one chapati equally for four cats?**

**Ans.** First of all I will fold the chapatti in two halves.

Then again I will fold it in further two halves. As we folded the circle in four equal parts to locate the centre in previous chapter.

Then I will tear off the chapati from the creased line.

**NCERT Textbook Pages 95-96**

**Half of Many Pieces**

Rani got a chocolate. She divided it equally and gave half to her friend Reena.

**1. Circle the portion that Reena got.**

**Ans.**

**2. How many pieces of chocolate are there?**

**Ans**. There are six pieces of chocolate.

**3. How many pieces were left with Rani?**

**Ans.** There are three pieces of chocolate left with Rani.

**NCERT Textbook Pages 96-97**

**Many Shapes from a Half Sheet**

Take a piece of paper. Cut the sheet into two equal triangles so that each triangle is equal to half of the sheet.

Shade the two triangles with different colours.

**1. Draw different shapes using these triangles. One such shape is shown here.**

**Ans.** Some shapes using these triangles are given here:

** NCERT Textbook Page 97**

**Many Ways to Cut into Half**

**1. In how many different ways can you cut a rectangle into half? Draw 5 different ways. Can you check if they are equal?**

**Ans.** Five different ways to cut a rectangle is as follows:

Each part of rectangle exactly coincides with the other part, so two parts are equal.

**2. In how many different ways can you cut a rectangle into four equal parts? Draw**

** five different ways. Can you check if they are equal?**

**Ans.** Cutting of a rectangle in four equal parts is shown in the figures given here.

As each part exactly coincides with the each of the remaining three parts, so they are equal.

**NCERT Textbook Page 98**

**Cutting the Cake**

Rajni’s father brought a cake. She divided the cake into 4 equal parts-for herself, her brother Raju, her father and her mother.

**1. Colour each share with different colours.**

**Ans.**

**2. How much does each get?**

**Ans.** Each person gets 1/4 of the cake.

**3. Mother gave her share of cake to Rajni. Now colour the total part that Rajni will get.**

**Ans.** By this way Rajni got = Her share + Her mother’s share

= 1/4+1/4

= 1/2 part of the cake

**4. Out of 4 parts Rajni will get______ Parts which is equal to half of the cake**

** So, she can write it as 1/4 or 1/2**

**Ans.** Out of 4 parts Rajni will get 2 parts.

So, she can write it as 2/4 or 1/2

**5. Colour the share Raju got.**

**Ans.**

**6. How much of the cake do Rajni and Raju together get? Colour their total share.**

** Altogether they get 3 parts out of 4, so we can write it as 3/4**

**Ans.**

**NCERT Textbook Page 99**

**Greedy Kundu**

First pumpkin seller – 1/4 of this pumpkin is for Rs 10.

**1. This full pumpkin will cost Rs______ .**

**Ans.** The cost of 1/4 pumpkin = Rs 10

Therefore, cost of one pumpkin = Rs 10 Ã· 1/4

= Rs 10 x 4/1

= Rs 40.

**2. Kundu-how much of this pumpkin will I get for 110? Second pumpkin seller-Half**

** This full pumpkin will cost Rs______**

**Ans.** If cost of half pumpkin is Rs 10

Therefore, the cost of full pumpkin = Rs 10 + Rs 10

= Rs 20

**NCERT Textbook Page 100**

**Using a Price List**

**1. How much does 1/2 kg of tomatoes cost?**

**Ans.**

The cost of 1 kg of tomato = Rs 8

Therefore, the cost of 1/2 kg tomato = Rs 8 Ã·2

= Rs4.

**2. Which costs moreâ€”1/2 kg of onions or 1/4 kg of carrots?**

**Ans.** The cost of 1/2 kg of onion = cost of 1/2 kg of onion/2

= Rs 10/2 = Rs 5

Cost of 1/4 kg of carrot = Cost of 1/4 kg of carrot/4

= RS 16/4

= Rs 4

The price of 1/2 kg of onions is more than the cost of 1/4 kg of carrots.

**3. What is the price of 3/4 kg of potatoes?**

**Ans.** The cost of 1 kg of potatoes = Rs 12

Therefore, the cost of 3/4 kg of potatoes = Rs 12 x 3/4

= Rs 36/4

= RS 9.

**4. Keerthi is going for shopping. She has only Rs 20 with her. Can she buy all the things in her shopping list?**

**Ans.** The cost of 1/2 kg of tomato =RS 8 x 1/2 = Rs 4

The cost of 1/4 kg of potato = Rs 12 x 1/4 =Rs 3

Cost of 1/2 kg of onion =Rs 10 x 1/2 = Rs 5

Cost of 1/4 kg of carrot = Rs16 x 1/4 =Rs 4

Cost of 1 kg of pumpkin = Rs 4 Total

cost =Rs4+Rs3+Rs5+Rs4+Rs4=Rs 20.

So, she can purchase all things in the price list managing as written above.

**NCERT Textbook Pages 101 -103**

**Practice Time**

**(a) What part of the whole is coloured? write below each shape.**

**Ans.**

**(b) Colour that part of the shape which is written below:**

**Ans.**

**(c) Cut in half draw in a line which devided these shapes into half.**

**Ans.**

**(d) Colour half the number of shapes as shown here.**

**Ans.** The coloured shape is given here

** (e) Colour 1/4 of these shapes.**

**Ans.** The coloured shapes are given as

**(f) Match the coloured part as shown.**

**Ans.**

** (g) Make the other half**

**1/2 of the picture is drawn here. Can you complete the picture by drawing the other half?**

**Ans.** Completed pictures.

**(h) This is a quarter of a picture. Can you complete it? How many more quarters will you draw to complete it?**

**Ans.** To complete this picture three more quarters will be needed to draw.

**NCERT Textbook Page 103**

**Half and Quarter of a Metre**

**1. Using your string, draw a line of length 1/2 metre on the floor. How many centimetres long is the line?**

**Ans**. The line is 50 cm long.

**2. So,**

** 1/2 metre =_________ cm**

** 1/4 metre =_________ cm**

** 3/4 metre =_________ cm**

** Can you see that when we add 1/2 and 1/4 we get 3/4?**

**Ans.**

1/2 metre = 100 cm x 1/2 = 50 cm

1/4 metre = 100 cm x 1/4 = 25 cm

3/4 metre = 100 cm x 3/4 = 75 cm

When 1/2 and 1/4 is added

We get 1/2+1/4=2+1/4=3/4

We can see that we get 3/4 by adding 1/2 and 1/4.

**NCERT Textbook Page 104**

**Sharing Milk**

**1. This bottle is full of milk and it holds one litre. The milk is put into 4 other bottles so that each bottle has 1/4 litre of milk.**

** Shade the bottles to show the level of milk in each.**

**Ans.** In the figures given under, the level of the milk is marked.

**2. How many millilitres of milk does each bottle have?**

**Ans.** Each bottle have 1000 mL x 1/4 = 250 mL of milk. .

**3. Shan poured 1 litre of milk into two bottles so that the first bottle holds 3/4 litre and the other holds 1/4 litre.**

** (a) Shade the level of milk in each bottle.**

** (b) How many millilitres of milk does each bottle hold?**

**Ans.**

(a) !’he level of milk in each bottle is given here

(b) The first bottle which holds 3/4 litre of milk has 750 mL of milk. The second bottle which holds 1/4 litre has 250 mL of milk.

**NCER.T Textbook Page 105**

**Balance the Weight**

**1. Choose from the weights above to make the two pans equal. In how many ways can you do it?**

**Ans.** This can be done in many ways. Some ways are given here.

(i) 1 kg + 500 gm + 500 gm

(ii)1 kg + 500 gm + 250 gm + 250 gm

(iii)1 kg + 500 gm + 200 gm + 200 gm + 100 gm

(iv)1 kg + 250 gm + 250 gm + 250 gm + 200 gm + 50 gm

(u) 1 kg + 200 gm + 200 gm + 100 gm + 500 gm

**(a) Draw the weights in the empty pan.**

**Ans.** To balance the pan I put 1 kg + 500 g + 500 g weights in empty pan.

**(b) In how many different ways can you balance this weight of 3/4 kg?**

** 1._______2._______3._______**

**Ans.**3/4 kg = 1000 gm x 3/4 = 750 gm

1.250 gm + 250 gm + 250 gm

2.250 gm + 250 gm + 200 gm + 50 gm

3.500 gm + 250 gm.

**NCERT Textbook Page 106**

**Why is it Wrong?**

**1. Kannan shaded some parts as shown. But his friend Mini says that it is wrong. Explain why it is wrong.**

**Ans.** The 2 parts out of 5 parts in the rectangle is coloured, so it is 2/5 part coloured. In the triangle it is not clear that how many parts of it is coloured. But it is clear that less than 1/2 part is coloured. So 1/2 is wrong.

**Practice Time**

**1. There are 60 mangoes. 1/2 of them are ripe. How many mangoes are ripe?**

**Ans.** Total number of mangoes = 60 Half of them are ripe

Therefore, number of ripe mangoes = 1/2 x 60

= 30 mangoes.

Hence, 30 mangoes are ripe.

**2. There are 32 children. 1/2 of them are girls. How many children are boys?**

**Ans.** Total number of children = 32

Half of them are girls, obviously half are boys.

Therefore, half of 32 =1/2 x 32 = 16 Hence, 16 children are boys.

**3. There are 20 stars. A quarter of them are red. How many stars are red? How many stars are not red?**

**Ans.** Total number of stars = 20

1/4 of them are red

Therefore, number of red stars = 1/4 x 20

= 5 stars

Number of red stars = 5

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