This chapter measuring weights using balance in kilograms and grams, addition and subtraction of weights The solutions for Math-Magic Chapter-12 have been created and verified by our experienced subject matter experts, according to the CBSE syllabus and guidelines of NCERT. For practice, our subject matter experts have created very interactive, activity-based, and Image-based worksheets on these topics to enhance learning.

Download the NCERT Solutions for How Heavy? How Light? in PDF

Question 1 :

Make groups of three things. For example — eraser, ball, and paper. Use the balance to arrange them in order of weight – the lightest, the one with an in-between weight, and the heaviest. Complete the table with at least five examples.

Answer :

Select three things and group them according to their weights as – the lightest, the one with an in-between weight, and the heaviest. Answers may vary based on the things. A sample answer is:

Question 2 :

Find out the total weight they had loaded on the cart.

Answer :

Items loaded in the carts are – a water tank, five sacks of wheat, three tables, an almirah, four chairs, two mattresses, three sacks of rice, a bamboo ladder, and pots and pans.

Step 1: Weight of 1 sack of wheat is 100 kg. Therefore, the weight of 5 sacks of wheat is 5 × 100 = 500 kg.

Step 2: Weight of 1 table is 10 kg. Therefore, the weight of 3 tables is 3 × 10 = 30 kg.

Step 3: Weight of 1 chair is 5 kg. Therefore, the weight of 4 chairs is 5 × 4 = 20 kg.

Step 4: Weight of 1 mattress is 20 kg. Therefore, the weight of 2 mattresses is 2 × 20 = 40 kg.

Step 5: Weight of 1 sack of rice is 35 kg. Therefore, the weight of 3 sacks of rice is 3 × 35 = 105 kg.

Step 6: Draw a table and enter the items loaded in the cart and their weights.

Thing loaded | Weight |

Water tank | 50 Kg |

5 sacks of wheat | 500 Kg |

3 tables | 30 Kg |

An almirah | 70 Kg |

4 chairs | 20 Kg |

2 mattresses | 40 Kg |

3 sacks of rice | 105 Kg |

A bamboo ladder | 10 Kg |

Pots and pans | 10 kg |

Step 7: Add all the weights to get the total weights. 50 + 500 + 30 + 70 + 20 + 40 + 105 + 10 + 10 = 835 kg Therefore, the total weight loaded in the cart is 835 kg.

Question 3 :

** **Which things should be removed so that the weight of the load is not more than 700 kgs?

Answer :

Total weight loaded in the cart is 845 kg.

835 – 700 = 135

Hence, things that will together weigh 135 kg or more should be removed from the cart. Answers may vary. One example is:

The weight of 3 sacks of rice is 105 kg, 4 chairs are 20 kg and a bamboo ladder is 10 kg. Since, 105 + 20 + 10 = 135, therefore these items can be removed so that the weight of the load is not more than 700 kgs.

Question 4 :

Now you also make your own balance. Write down how you made it. Also draw a picture of your balance in the box below.

Answer :

Make a balance on your own and write down the steps to make the balance. Also, draw the picture of the balance you have made. Answers may vary from student to student.

Question 5 :

Mannu and Jaiju put a pencil and a geometry box in the two pans of the balance. Which pan will go down? Why? Draw a picture to show it.

Answer :

The pan with the geometry box will go down because the weight of the geometry box is more than the weight of the pencil.

Question 6 :

Make pairs of different things and use the balance to decide which is heavier. First guess which thing will take the pan down and then check with your balance.

Answer :

Answers may vary based on the pair of things you select. Select the pairs of different things and observe their weight to answer this question.

Question 7 :

Can you find your own weight using this balance?

Answer :

No, this balance is not used to find your weight.

Question 8 :

The soap weighs ____________ grams (g).

Answer :

** **Answers may vary. In general, the weight of a small soap is 50 grams.

Question 9 :

Close the packet with a rubber band or string. Now stick a strip of paper and write '____ g' on it.

Answer :

The weight of the packet is equal to the weight of the soap. The answer will vary based on your previous answer.

Question 10 :

** **If you put the soap and the weight you just made together in a pan, how many grams will both of these weighs?

Answer :

The total weight will be equal to the sum of the weight of the soap and the sand packet. Answers will vary based on your previous answer. A sample answer is:

Weight of the soap is 50 g. Weight of the packet is 50 g. Therefore, the total weight is

50 + 50 = 100 g.

Question 11 :

** **Now make different weights – 150 g, 200 g and 250 g. You can use soaps of different weights for this. Also make some bigger weights of 500 g, 1000 g, and 750 g. Use your weights to weigh different things and write in your notebook.

Answer :

Perform the activity on your own as directed.

Question 1 :

Which pan of the balance will go down? Show by drawing an arrow.

Answer :

Step 1: Add 700, 245 and 55 to get the total weight on the left pan.

700 + 245 + 55 = 1000 g

Step 2: Add 66 and 254 to get the total weight on the right pan.

600 + 254 = 854 g

Step 3: The weight on the left pan is more than the weight on the right pan. Therefore, the left pan will go down.

Question 2 :

Which pan of the balance will go down? Show by drawing an arrow.

Answer :

Step 1: Add 196 and 20 to get the total weight on the left pan.

196 + 20 = 216 g

Step 2: The weight on the left pan is more than the weight on the right pan. Therefore, the left pan will go down. Mark an arrow on the left pan.

Question 3 :

Which pan of the balance will go down? Show by drawing an arrow.

Answer :

Step 1: Add 75 and 36 to get the total weight on the left pan.

75 + 36 = 111 g

Step 2: Add 100 and 63 to get the total weight on the right pan.

100 + 63 = 163 g

Step 3: The weight on the right pan is more than the weight on the left pan. Therefore, the right pan will go down.

Question 4 :

Name 5 things that we usually buy—

Answer :

Answers may vary based on the items that you buy regularly. A sample answer is:

Question 5 :

Which pan of the balance will go down? Show by drawing an arrow.

Answer :

Step 1: Add 75 and 75 to get the total weight on the left pan.

75 + 75 = 150 g

Step 2: Add 140 and 35 to get the total weight on the right pan.

140 + 35 = 175 g

Step 3: The weight on the right pan is more than the weight on the left pan. Therefore, the right pan will go down.

Question 6 :

Which pan of the balance will go down? Show by drawing an arrow.

Answer :

Step 1: Add 200 and 105 to get the total weight on the left pan.

200 + 105 = 305 g

Step 2: Add 250 and 150 to get the total weight on the right pan.

250 + 150 = 400 g

Step 3: The weight on the right pan is more than the weight on the left pan. Therefore, the right pan will go down.

Question 7 :

How much does an inland letter cost?

Answer :

An inland letter is for Rs 2.50 that is 2 rupee and 50 paise.

Question 8 :

** **Is the weight on any of the pans equal to 1 kilogram? Mark it.

Answer :

We know that 1000 g = 1 kg. Therefore, the weight on the left pan of the third balance is equal to 1 kilogram.

Question 9 :

How many grams are there in 1 kg?

Answer :

There are 1000 grams in 1 kilogram.

1 kg = 1000 g.

Question 10 :

Which is heavier — one kilogram cotton or one kilogram iron?

Answer :

One kilogram weight is the same for both iron and cotton. So, 1 kg iron and 1 kg cotton both are equal in weight

Question 11 :

Guess and write the weight of each thing he bought—in g or kg.

Answer :

The correct answer is:

Items | Weight |

Rice | 5 kg |

sugar | 10 kg |

Mustard seeds | 1 Kg |

wheat | 3 Kg |

Dal | 500g |

Tea | 250g |

Pepper | 25g |

Question 12 :

Ritu is weighing her toys. She wants to know if her tractor is heavier than her car. How would you help her to find out quickly?

Answer :

Ritu should place the car and the tractor on each of the pan of a balance. The pan with the toy that goes down will be heavier.

Question 13 :

Guess which is the heaviest — a real car, a bus or a tractor?

Answer :

A bus is the heaviest when compared to a car or tractor.

Question 14 :

** **Which is the heaviest thing you have seen?

Answer :

Answer this question based on your experience. Answers may vary. One example is:

The heaviest thing that I have seen is a train.

Question 15 :

If I put 2 cars, will the tractor still be heavier?