How Heavy?How Light? – Class 4 /Maths.

Chapter 12 of NCERT/CBSE Class 4 Maths is about How Heavy? How Light?. Here in this lesson you can find out practice problems regarding weight.

NCERT SOLUTIONS FOR CLASS 4 MATHEMATICS
How Heavy? How Light? – Chapter 12.
Answer the following:

1. The weight of the following things is given below.
   A sack of wheat – 100 kg (5 items)
   A sack of rice – 35 kg (3 items)
   Water tank – 50 kg (1 item)
   Almirah -70 kg (1 item)
   A table – 10 kg (3 items)
   A chair – 5 kg (4 items)
   A mattress – 20 kg (2 items)
   Bamboo ladder – 10 kg (1 item)
   Pots and pans – 10 kg
   a) Find out the total weight they had loaded on the cart?
   b) Which things should be removed so that the weight of the load is not more than 700 kg?
2. Mannu and Jaiju put a pencil and a geometry box in the two pans of the balance. Which pan will go down? Why?
3. Which pan of the balance will go down?
   a) 25g & 40g or 35g & 40g
   b) 75g & 75g or 35g & 140g
   c) 55g, 245g & 700g or 254g & 600g
   Is the weight of any of the pans equal to 1 kg?
   How many grams are there in 1 kg?
4. Name 5 things that we usually buy
   a) In grams
   b) In kilograms
5. Which is heavier?
   One kilogram cotton or one kilogram iron.
6. Write the weight of each thing he bought – in g or kg?
   Items/Weight: Rice/5
   Sugar /1
   Mustard seeds / 10
   Wheat / 3
   Dal / 500
   Tea / 250
   Pepper/25
7. Which is the heaviest? A real car, a bus, or a tractor.
8. Which is the heaviest thing you have seen?
9. Look at the postal rates given in the chart:
   Postal items and postal rates in Rs.
   Single post card: 0.50
   Printed post card: 6.00
   Inland letter: 2.50
   Letter weighing
   i) 20g or less: 5.00
   ii) For every additional 20g: 2.00
   Parcel weighing:
   i) 50g or less: 5.00
   ii) For every additional 50g: 3.00
   a) How much will you have to pay for stamps on a letter weighing 50 grams?
   b) Akash wants to send a parcel of the Math Magic Textbook to his friend Rani in Chennai. The book weighs 200g. See the chart to find the cost of posting the book?
10. Rahul needs stamps of rupees 25 for his parcel. He went to the post office. Only stamps of Rs 1, Rs 2, Rs 5 and Rs 10 were there at that time. Using those stamps in how many different ways can he make Rs 25? Can you show 5 different ways?

ANSWERS:

1. a) Total weight
   = 100 x 5 + 35 x 3 + 50 x 1+ 70 x 1+ 10 x 3 + 5 x 4 + 20 x 2 + 10 x 1+10
   = 500 + 105 + 50 + 70 + 30 + 20 + 40 + 10 + 10
   = 835 kg
   b) Total weight = 835 kg
   Required weight = 700 kg
   Therefore we need to reduce 835 – 700 = 135 kg weight from the cart.
   From the table we can see that the weight of 3 sacks of rice = 105 kg
   The weight of 3 tables = 30 kg
   Total weight of these two = 105 + 30 = 135 kg
   Therefore, 3 sacks of rice and 3 tables can remove from the cart to make the weight equal to 700 kg.
2. The weight of a geometry box is more than a pencil. Hence the pan that has geometry box will go down.
3. a) 25 + 40 = 65g
   35 + 40 = 75 g
   Since 75 are greater than 65, the pan with 35g & 40g will go down.
   b) 75 + 75 = 150g
   35+ 140 = 175 g
   Since 175g is greater than 150g, the pan with 35g & 140g will go down.
   c) 55 + 245 + 700 = 1000g
   254 + 600 = 854g
   Since 1000g is greater than 854g, the pan with 55g, 245g & 700g will go down.
   The pan with weights 55g, 245g and 700g is equal to 1 kg.
   1000 grams are there in 1 kg.
4. a) In grams – Pepper , Tea, Mustard seeds, Cardamom, Chilli powder.
   b) In kilograms – Onion, Rice, Vegetables, Fruits, Wheat.
5. Both have the same weight 1 kg.
6. Rice – 5kg
   Sugar – 1 kg
   Mustard seeds – 10kg
   Wheat – 3 kg
   Dal – 500g
   Tea – 250g
   Pepper – 25g
7. Among these the heaviest thing is a bus.
8. Train (According to you)
9. a) Letter weighing up to 20g = 5 rupees
   For every additional 20g = 2 rupees
   For additional 10g = 2 rupees
   Total cost = 5 + 2 + 2 = 9 rupees.
   b) Cost of parcel weighing 50g = 5 rupees
   For every additional 50g = 3 rupees
   For additional 150g = 3 x 3 =9
   Total cost = 9 + 5 =14 rupees.
10. He can make 25 in the following different ways:
    1 x 25, that is 25 stamps of 1 rupee.
    2 x 12 + 1, that is 12 stamps of 2 rupees and 1 stamp of 1 rupee.
    5 x 5, that is 5 stamps of 5 rupees.
    10 x 2 + 5, that is 10 stamps of 2 rupees and 1 stamp of 5 rupees.
    10 + 5 x 3, that is 1 stamp of 10 rupees and 3 stamps of 5 rupees.