# NCERT Solutions Class 4 Maths Chapter 12

## NCERT Solutions for Class 4 Maths Chapter 12 – How Heavy? How Light?

Students learn about weight and how to  weigh   objects by examining how light they are. This is one of the important concepts in mathematics that the students must learn at this growing stage. We need to measure a lot of things in our day-to-day life. We measure distance, length, weight, time, and temperature. All the things we measure are counted with the help of a unit. A unit is the smallest quantity of something that we can measure.

This chapter introduces the concept of weights. As the name suggests, students will be able to identify how heavy or light different objects around them are. Understanding the concept of weights is important for everyone to apply them in various situations in our daily lives.

## NCERT Solutions for Class 4 Maths Chapter 12 – Chapter Notes

#### How Heavy Is This?

Jaiju and Mannu were shifting their house. They loaded all their things on a horse cart. They loaded various things, such as five sacks of wheat, three tables, two mattresses, three sacks of rice, a water tank, a bamboo ladder, pots and pans, etc. The load became so heavy that the horse couldn’t even move. That is when their father told them that the horse was not well and could not carry a weight of more than 700 kg.

Their father gave them an estimate of the load on the sick horse.

 Things Loaded Weight Number of items Their total weights A sack of wheat 100 kg 5 5 × 100 = 500 kg A sack of rice 35 kg 3 3 × 35 = 105 kg Water tank 50 kg 1 1 × 50 = 50 kg Almirah 70 kg 1 1 × 70 = 70 kg A table 10 kg 3 3 × 10 = 30 kg A chair 5 kg 4 4 × 5 = 20 kg A mattress 20 kg 2 2 × 20 = 40 kg Bamboo ladder 10 kg 1 1 × 10 = 10 kg Pots and pans 10 kg 1 1 × 10 = 10 kg

The total weight of the things turns out to be 835 Kg.

The items that were piled onto the cart were both large and heavy. A large balance is required to measure the weight of such heavy and large objects. Jaiju and Mannu created their balance with the help of a stick, two lids and a thick thread.

The siblings then used the balance to find the weight that needed to be removed from the horse so it could move easily. As the horse cannot carry a load of more than 700 kgs, students can find out with the help of simple subtraction that weight that they should remove;

835-700 = 135 kgs of weight should be removed from the horse. Jaiju and Mannu start to weigh the items on their balance:

The weight of 3 bags of rice = 105 kg.

The weight of 3 tables = 30 kg

The total weight of both of these two things = is 105 + 30

= 135 kg; therefore, to make the weight 700 kg, they should remove three sacks of rice and three tables from the horse cart.

Students can learn more about weights from the detailed description of the NCERT Solutions For Class 4 Maths Chapter 12 provided by Extramarks. Students can easily access this resource from the Extramarks website.

#### Making Weights

To better understand the concept of weights, students should make their weights by conducting this activity. Students can conduct this activity in pairs. They would require a balance, weights, a cake of soap, plastic packets, sand and rubber bands.

The packet of soap will weigh grams written on the packet. Students can use the soap to make their weights. They can follow the simple steps mentioned below:

1. Take a plastic bag and arrange it on one side of the balance.
2. Put the soap on the other plate of the balance.
3. Keep adding the sand in the plastic bag until both the balance plates are equal.
4. When both the plates of the balance come at an equal level, close the plastic bag and put a tag on the plastic bag. It has the same weight in grams as the soap.

Now students can make weights of 150 g, 200 g and 250 g. They can use soaps of different

weights for this purpose. You can also make some bigger weights of 500 g, 1000 g, and 750 g with the help of this method.

#### Grams and Kilograms

Here are a few things students can measure in grams and kilograms.

 In grams In kilograms, Turmeric powder Tomatoes Mustard seeds Sugar Chilli powder Wheat Cardamom Bananas Cloves Rice

Students can also find out things that weigh differently in grams and kilograms. They can take examples from everyday household items to find out more things that are measured differently. Students can construct a new table with their different examples.

#### Which is Heavier

A teacher is trying to explain to his students what is heavier. He asks whether one kilogram of cotton is heavy or one kilogram of iron. In actuality, both things weigh the same. While 1 kg of iron might feel heavier than 1 kg of cotton, it is due to density, a concept that students will learn in further classes.

To understand weights, students can visit the Extramarks website to access the NCERT Solutions For Class 4 Maths Chapter 12. Students will have to register on the website to access many useful resources.

#### Dinesan Went Shopping

Dinesan went shopping and purchased a few items. But his younger brother ripped the bill where the weights were written. With the help of the information students learned in the NCERT Solutions For Class 4 Maths Chapter 12, it is easy to determine the weights of the purchased items. When students solve this problem, their solutions should be similar to the table below.

 Items Weight Rice 5 kg Sugar 1 kg Mustard seeds 10 g Wheat 3 kg Dal 500 g Tea 250 g Pepper 25 g

#### Car and Tractor

Ritu is weighing her toys with the help of a balance, as seen in the image above. She wants to know that between her toy car and her toy tractor is the heaviest. In the above section, the students learned how to have different weights using a bar of soap and some sand. When the plates on either side of the balance were at an equal height, it meant that the things on both sides had a similar weight.

So, in this case, if Ritu wishes to find out which is the thing that has a greater weight, then she has to notice which side of the balance goes down. The toy which goes further down in the balance is considered the heavier one.

#### Broken Stones

Abdu sells firewood. In his shop, there was a 13-kilogram stone. He used it to weigh firewood. The stone dropped to the ground one day and split into three pieces weighing 2 kg, 5 kg, and 6 kg.

However, Abdu was extremely intelligent. He used those three pieces to weigh firewood ranging in weight from one kilogramme to nine kilograms.

Abdu places a 6kg stone piece on one side of the balance and a 5 kg stone piece on the other. As the weight of the 6 kg stone increases, it goes further down. Abdu starts pilling on wood over the 5 kg stone side. He continues adding wood until the level of the balance becomes equal. Hence Abdu gets to know that the weight of the pile of wood is 1 kg.

Similarly, Abdu can use a variety of combinations to measure the weight of various piles of wood for his shop. For example, he can measure 4 kg of wood using 6kg and 2kg of stone. He can place the 6 kg stone on one side of the balance and the 2 kg stone on the other.

Abdu will have 4 kg of wood when both sides of the balance come to an equal level. Hence similarly, he will successfully find about 3kg, 7 kg and 9 kg of wood using stones of different weights.

#### Post Office

 Postal Items Postal Rates(In Rs) Single postcard 0.50 Printed postcard 6.00 Inland Letter 2.50 Letter weighing – i) 20 grams or less ii) For every additional 20 grams 5.002.00 Parcel weighing – i) 50 grams or less ii) For every additional 50 grams 5.003.00

Hence from this above table, students can easily find out what rates will be charged for a particular amount of weight to be sent via postal service.

1. For a letter weighing 50 grams, it is given that for 20 or less, the postal rates are 5 Rs. And for every additional 20g, the postal rate is 2 Rs. 50 grams = 20 grams + 20 grams + 10 grams. So, the stamp rate for the 50g letter = is 5 + 2 + 2 = 9. The total rate paid for the stamps = 9 Rs.
2. Suppose Akash wants to send a parcel of the Math Magic book to his friend Rani residing in Chennai. The book weighs 200 g. According to the chart, the cost of sending the book will be calculated as follows;

Parcel weighing 50 gms= Rs. 5

Every Additional 20 gms = Rs. 3.

Hence the additional cost for the parcel = 9 ( As the weight of the parcel can be divided into 50+50+50+50, which implies that there are three additional 50 gms to the parcel weight)

Total cost= 5 + 9 = Rs. 14 for sending the book to Rani in Chennai.

1. Total weight of the parcel is 230 g. The cost of a 50 gms parcel is Rs 5, and for every extra 50g, the cost is Rs 3. 230 = 50 grams + 50 grams + 50 grams + 50 grams + 30 grams. Thus, the cost of the stamps = Rs 5 + 3 + 3 + 3 + 3 = Rs.17. Hence, the total cost of a parcel weighing 230g is 17 rupees. Parcel Weight = 230g Cost of stamps = 17Rs.

#### How Many Stamps

For his package, Rahul needs stamps costing Rs. 25. He visited the post office. There were only Rs. 1, Rs. 2, Rs. 5, and Rs. 10 stamps available at the time. There are many different ways he can make Rs 25 with those stamps, which are mentioned below given in NCERT Solutions For Class 4 Maths Chapter 12:

1. Rs 1 × Rs 25 = Rs 25
2. Rs 2 × Rs 12 + Rs 1 = Rs 24 + Rs 1 = Rs 25
3. Rs 5 × Rs 5 = Rs 25
4. Rs 10 × Rs 2 + Rs 5 = Rs 20 + Rs 5 = Rs 25
5. Rs 10 + Rs 5 × Rs 3 = Rs 10 + Rs 15 = Rs 25

#### Am I Fit Or Fat

Now, you can also fill the table by finding the age, height and weight of any five people in your class; the table can look something like the one mentioned below:

 Name Age Height Weight Shyam 7 4 feet 4 inches 24 kg Rama 6 4 feet 2 inches 20 kg Anjali 10 5 feet 2 inches 30 kg Aakash 9 5 feet 1 inch 25 kg Rakesh 8 4 feet 9 inches 22 kg

The table can look different for different students.

#### How Many Oranges

All oranges are the same weight. The two papayas share the same weight. The weights in the first and second balances are the same. How many oranges are required to balance the weight in the third?

In the first balance –

1 Mango + 1 Orange = 3 Oranges,

1 Mango = 3 Oranges – 1 Orange

1 Mango = 2 Oranges.

Hence, 1 Mango = 2 Oranges

In the second balance –

2 Papaya = 2 Oranges + 1 Mango

2 Papaya = 2 Oranges + 2 Oranges [1 Mango = 2 Oranges]

2 Papaya = 4 Oranges.

Hence, 1 Papaya = 2 Oranges

In the third balance –

1 Papaya + 1 Mango = 2 Oranges + 2 Oranges [1 Papaya = 2 Oranges and 1 Mango = 2 Oranges]

1 Papaya + 1 Mango = 4 Oranges,

Therefore, in the third balance, 4 Oranges will balance 1 Papaya and 1 Mango together.

#### Find That Marble

There are three marbles of the same size, but one is significantly larger, heavier or lighter compared to the other two. Can you figure out which marble is heavier or lighter? Students can only use a balance twice.

Consider the yellow, red, and blue marbles to be the letters Y, R, and B, respectively. First, place Y and R on the pans of a balance. There are two possible outcomes: balanced or unbalanced.

1. The weights are balanced;

R and Y have identical weights. As a result, B is the stone that is either heavier or lighter. Now, place B and Y on opposite sides of the scale and weigh them. If the pan containing B falls, B is the heavier marble. If the pan containing Y falls, then B is the lighter marble.

2. The weights are unbalanced;

Put R and B on the balance if the weight of Y is less than R. When R and B are equal, the lighter marble is Y. If B is lighter than R, R is the heavier marble.

If Y’s weight is larger than R’s, place R and B on balance. If R and B are both equal, Y is the heavier marble. R is the lighter marble if B is heavier than it.

### NCERT Solutions Class 4 Maths Chapter-wise List

Chapter 1 – Building With Bricks
Chapter 2 – Long And Short
Chapter 3 – A Trip To Bhopal
Chapter 4 – TickTickTick
Chapter 5 – The Way The World Looks
Chapter 6 – The Junk Seller
Chapter 7 – Jugs And Mugs
Chapter 8 – Carts And Wheels
Chapter 9 – Halves And Quarters
Chapter 10 – Play With Patterns
Chapter 11 – Tables And Shares
Chapter 13 – Fields And Fences
Chapter 14 – Smart Charts

### NCERT Solutions for Class 4 Maths Chapter 12 Exercises & Answer Solutions

NCERT Solutions for Class 4 Mathematics Chapter 12 are given by subject matter experts so that students can answer different questions asked in the examination and are prepared based on the latest CBSE curriculum. Students may solve previous years’ question papers to score well in exams.

Students may click on the link below to access the question and answer solutions based on NCERT textbook Chapter 12- How heavy? How light?

• NCERT Textbook – Class 4 Mathematics Chapter 12 – Questions and Answers

Apart from NCERT solutions for Class 4 mathematics Chapter 12, students may explore NCERT solutions for all primary and secondary classes by clicking on the links below.

• NCERT solutions class 12
• NCERT solutions class 11
• NCERT solutions class 10
• NCERT solutions class 9
• NCERT solutions class 8
• NCERT solutions class 7
• NCERT solutions class 6
• NCERT solutions class 5
• NCERT solutions Class 4
• NCERT solutions class 3
• NCERT solutions class 2
• NCERT solutions class 1

### Key Features of NCERT Solutions for Class 4 Maths Chapter 12

• NCERT solutions are provided in a detailed stepwise manner.
• Students can better understand the concepts of weights by referring to these NCERT solutions.
• Students can refer to the solutions in this chapter to prepare effectively for their exams.