NCERT Solutions for Class 4 Maths Mela Chapter 8 Weigh It, Pour It

Page 115

1. Look at the pictures given and write the names of the animals from heaviest to lightest.

Answer:
Elephant, Giraffe, Dog, Squirrel, Rat.

2. Write the name of the heaviest object in your home. How did you know?
Answer:
Heaviest object in my home is Almirah. I know it’s the heaviest because it cannot be moved easily by one person and requires multiple people to lift.

3. Do you carry you school bag with ease or with some efforts?
Answer:
I carry my school bag with some effort, as it contains several books and notebooks.

4. Write the name of the heaviest book in your bag. How did you know?
Answer:
The heaviest book in your bag: Mathematics textbook.
I know it’s the heaviest because when I hold it individually, it feels heavier than my other books.

5. What is your weight? How did you know?
Answer:
My weight is approximately 32 kg. I know this because I measured it on a weighing scale at home.

Page 115

Fun at Vegetable Market

Rita and Shabnam went to the market to buy some fruits and vegetables. They saw the vegetable seller weighing vegetables.
What do you think will be the weigh of the half pumpkin?

Answer:
Yes, because the weight of half pumpkin is approximately 1-2 kg.

Page 116

Let Us Do

Estimate the weight of the following and put a tick mark (✓) in the appropriate cell. Try to verify if your guess is correct by using a weighing balance.

Answer:

Page 117

Let Us Find

1. How many 250 g daal packets will balance one 500 g daal packet?
Answer:
2 packets of 250 g will balance one 500 g packet.
So, 250 g = 1/2 of 500 g.

2. Drawing arrows to indicate which side the pan balance will tilt? One is shown for you.

Answer:

3. Match the unit convenient for measuring each of the following objects?

Answer:

Page 119

Let Us Do

1. How many erasers will weigh the same as a 50 g Haldi packet?______
Answer:
5 erasers

2. A 100 g soap bar will weigh the same as __________ erasers.
Answer:
A 100 g soap bar will weigh the same as “10” erasers.

3. _________ erasers will weigh the same as 250 g sugar.
Answer:
“25” erasers will weigh the same as 250 g sugar.

Page 119

Let Us Think

Boxes of Sweet
Mr Shrinathan, a sweet shop owner has several orders for 1 kg Kaju-katli but he has to pack them in different sized boxes.

Write down the number of boxes needed to pack 1 kg Kaju-katil in the blank space:
1. Mr Das wants the sweets in boxes weighing 500 g each. _____________
Answer:
2 boxes (since 2 × 500 g = 1 kg)

2. Mrs Fernandes wants the sweet in boxes weighing 250 g each. ______________
Answer:
4 boxes (since 4 × 250 g = 1 kg)

3. Mrs Khan wants the sweets in boxes weighing 100g each. ______________
Answer:
10 boxes (since 10 × 100 g = 1 kg)

4. Mr Patel wants the sweets in boxes weighing 50 g each. ___________
Answer:
20 boxes (since 20 × 50 g = 1 kg)

Page 120

Weighing Machines

1. Do you know the different types of weighing types of weighing machines used to weigh different objects?

Answer:
(a) A balance scale (beam balance)
(b) A baby weighing scale
(c) A hanging scale
(d) A traditional market scale with weights
(e) A personal weighing scale.

Page 120

Let Us Do

Ask your parents and find the amount of consumption of the following items at your home in a month.

Answer:

Taran and his sister are lifting packets of flour, rice, and salt.
What do you think they are experiencing while lifting these packets?
Answer:
Heavier packets require more effort and strength. Some packets are easier for Taran to lift than his sister. The distribution of weight in the packet affects how easy it is to carry.

Have you ever lifted such packets at your home? What do you experience?
Answer:
My experience with lifting such packets: The heavier packets require me to use both hands and sometimes I need help from adults for very heavy packages.

Page 121

Let Us Do

1. Try to lift some objects around you and write the names of three objects that you can lift easily. Estimate and write their weights.
Answer:
► Pencil box (200 g)
► Water bottle (500 g)
► Lunchbox (300 g).

2. Now write the names of things that you can lift with a lot of effort. Estimate and write their weights.
Answer:
► School bag filled with books (4 kg)
► Chair (5 kg)
► Medium-sized bucket filled with water (8 kg)

3. How many 1 kg packets are in
a. 10 kg : ____________________
b. 20 kg : ____________________
c. 50 kg : ____________________
d. 25 kg : ____________________
Answer:
a. 10 kg: 10 packets
b. 20 kg: 20 packets
c. 50 kg: 50 packets
d. 25 kg: 25 packets

4. Match the objects in the left column with their estimated weights in the right column.

Answer:

Page 122

Measuring Capacity

Do you remember the 1 litre bottle? How much water does you water bottle hold?
Find the bottle and containers that can hold the following quantities of water. Write their names in the appropriate columns in the table given below.

Answer:

Page 123

Let Us Find

a) How many 500 ml bottles will fill a 1 l bottle?
Answer:
2 bottles (since 2 × 500 ml = 1000 ml = 1 l).

b) How many 250 ml bottles will fill a 1 l bottle?
Answer:
4 bottles (since 4 × 250 ml = 1000 ml = 1 l).

c) How many 100 ml bottles will fill a 1 l bottle?
Answer:
10 bottles (since 10 × 100 ml = 1000 ml = 1 l).

d) How many
250 ml in 1/2 l = _____________
250 ml in 750 ml = _____________
100 ml in 1/2 l = _____________
100 ml in 800 ml = _____________
Answer:
250 ml in 1/2 l = 2
250 ml in 750 ml = 3
100 ml in 1/2 l = 5
100 ml in 800 ml = 8.

Page 124

Let Us Do

1. Fina a dosing cup or a bottle of 10 ml and try to find how many 10 ml will fill a 100 ml bottle__________________
Answer:
10 doses (since 10 × 10 ml = 100 ml)

Find how many
a) 10 ml dosing cups will fill a 250 ml glass?
Answer:
25 dosing cups (since 25 × 10 ml = 250 ml)

b) 10 ml dosing cups will fill a 500 ml vessel?
Answer:
50 dosing cups (since 50 × 10 ml = 500 ml)

c) 10 ml dosing cups will fill a 1 l bottle?
Answer:
100 dosing cups (since 100 × 10 ml = 1000 ml = 1 l)

2. Take a 1 ml dropper and find out
a) How many 1 ml droppers will fill a 10 ml dosing cup?
Answer:
10 droppers (since 10 × 1 ml = 10 ml)

b) How many droppers will fill a teaspoon?
Answer:
5 droppers (since a teaspoon typically holds about 5 ml)

3. Find out how much of these liquids are used at a time:
a) Eye drops: Less than 1 ml at a time
b) Honey
c) Cough Syrup
d) Cooking Oil
Answer:
a) Eye drops: Less than 1 ml at a time
b) Honey: About 10-15 ml (1 tablespoon)
c) Cough Syrup: About 5-10 ml (1-2 teaspoons)
d) Cooking Oil: About 10-30 ml (for cooking a single dish)

4. Mr Krishna packages perfumed oils in different sized bottles. During a festival, the following customers asked for 1 l perfumed oils but in following customers asked for 1 l perfumed oils but in different sized bottles. Write the number of bottles each of them will get.
a) Ms Shetty wants bottles of 500 ml each _______
Answer:
2 bottles (since 2 × 500 ml = 1000 ml = 1 l)

b) Mr. Muthukumar wants bottles of 200 ml each
Answer:
5 bottles (since 5 × 200 ml = 1000 ml = 1 l)

c) Ms. Naini wants bottles of 100 ml each
Answer:
10 bottles (since 10 × 100 ml = 1000 ml = 1 l)

d) Ms. Kannan wants bottles of 50 ml each
Answer:
20 bottles (since 20 × 50 ml = 1000 ml = 1 l)

5. Estimate and verify by measuring. Use the bottles you have collected for this purpose (for examples, 500 ml , 250 ml, 100 ml, 50 ml, and 10ml).

Answer:

Page 125

Let Us Explore

Visit nearby shops and make a list of different items that are sold in the following quantities.

Answer:

Page 126

Let Us Find

a) How many litres of water do you drink in a day? How did you find out?
Answer:
About 2 liters. I found out by counting the number of glasses (about 8 glasses of 250 ml each).

b) How much water can a crow drink at a time?
Answer:
About 10-15 ml

c) How much milk do you drink in one day?
Answer:
About 300 ml (less than two glasses of 250 ml each).

d) How much water does an elephant drink in a day?
Answer:
About 150-200 liters.

Page 126

What do you use the most water for? What do you use the least water for? Compare this with a few others in your grade. In which activities is your water usage the same?
Answer:
Thinking about my daily activities that require water (bathing, drinking, washing hands, flushing toilets, watering plants, etc.)
I use the most water for bathing/showering or toilet flushing.
I use the least water for brushing teeth or washing hands.
When comparing with classmates, looks similar for almost all friends.

How much water may be used in the following activities?
a. Water for taking a shower
b. Watering crops in a field
c. Watering flowering plants
d. Washing clothes
e. ___________________
f. ___________________
Answer:
a) Water for taking a shower: About 20-30 liters.
b) Watering crops in a field: About 2000-5000 liters (depending on size).
c) Watering flowering plants: About 1-2 liters per plant.
d) Washing clothes: About 15-20 liters for hand washing or 50-100 liters for machine washing.
e) Washing hands: About 1-2 liters.
f) Brushing teeth: About 1-2 liters.

Page 127

Water Conservation in Everyday Life

Have you ever noticed a small drip of water flowing from your tap or water purifier? Have you considered how much water is actually being wasted?
Answer:
About 200-500 ml in an hour (depending on the size of the drip)

Take a container and put it under the leaking tap or water purifier for an hour. How much water is lost in an hour from just a slow drip? Did it surprise you?
Answer:
Water lost in an hour: About 150-300 ml

How much water is lost in a day?
Answer:
Water lost in a day: About 5-12 liters

How much do you think is lost in a week?
Answer:
Water lost in a week: About 35-84 liters

How would this wastage of water affects us?
Answer:
This wastage of water affects us:
► It leads to unnecessary water bills.
► Wastes precious drinking water.
► Creates water scarcity.
► Contributes to environmental problems.
► Reduces available water for essential needs.

This chapter is about the play with circles and circles. I hope you played some of such games that include circles in them. Now the question is how you found out the way to draw a perfect circle during the play. In the chapter you will see there are some of the ways to make circles in those circles are for just paper and too small to trace it on the ground. You need something bigger. So try to make one in the ground.

You might be able to use a waste bicycle tire which is laying around or maybe a string and stone so one can hold and stand in the middle and the other one can hold the string end and draw while walking in a circle and other people in the center will hold the string tight. The rule is simple that sting cannot be loose otherwise the circles will lose their shape.

You will also see this activity is being done in the chapter that makes this activity totally relevant because somehow in those the kids failed to draw a perfect circle with the help of a wooden stick.

The activity you have done is the solution even you will find it in the book not just that this activity will teach you the way the compass and pencil are being used to draw the lines.

Once you master the way to use the compass and pencil to draw the different sizes of circles you will find it easy to draw with the help of it because using this method you will be able to draw different designs that are given in the chapter and apart from it you can use your imagination to make such designs because pretty much everything around you has some form of circles in it. Like cars, trains, and its wheel, fruits like orange, even if you see from above your pencil is round.

Children need a lot of interesting exercises of making and measuring the radius of circles of different sizes. They can also make wheels and carts. Encourage children to explore their own designs with a compass. This will also give them more practice in drawing circles with a compass.