Chapter 8 of 14
Chapter 8: Who Is Heavier?
Mass / Weight (kg & g), Pan Balance, Pumpkin Prize & Grocery Packing | CBSE Session 2026–27
Core Pedagogical Competencies & Concepts
- Understanding mass and weight: heavier vs lighter.
- Standard units: Kilogram (kg) and Gram (g).
- 1 Kilogram = 1000 Grams (1 kg = 1000 g); 1/2 kg = 500 g.
- Balancing pans: when both pans are level, weights are equal.
All Textbook Exercises & In-Text Tasks (17 Questions)
100% Complete Ingestion
Q1
Weight Unit Selection • Real-World Items
State whether you would measure the weight of the following in 'Kilograms (kg)' or 'Grams (g)': (a) A sack of wheat, (b) A gold ring, (c) A geometry compass, (d) A bag of cement.
[2 Marks]
✅ Step-by-Step Solution & Working
Appropriate Units:
• (a) Sack of wheat: Kilograms (kg) (heavy staple, e.g., 25 kg)
• (b) Gold ring: Grams (g) (light jewellery, e.g., 5-8 g)
• (c) Geometry compass: Grams (g) (light tool, e.g., 50 g)
• (d) Bag of cement: Kilograms (kg) (heavy industrial bag, 50 kg).
• (a) Sack of wheat: Kilograms (kg) (heavy staple, e.g., 25 kg)
• (b) Gold ring: Grams (g) (light jewellery, e.g., 5-8 g)
• (c) Geometry compass: Grams (g) (light tool, e.g., 50 g)
• (d) Bag of cement: Kilograms (kg) (heavy industrial bag, 50 kg).
CBSE Step-by-Step Marking Scheme
Correct units for wheat and cement (kg)
1.0 M
Correct units for ring and compass (g)
1.0 M
Q2
Balance Calculations • Grams & Kilograms
A grocery shopkeeper has to weigh 2 kg of sugar. He has only 500 g weights. (a) How many 500 g weights must he put on the weight pan? (b) How many grams are in 2 kg?
[2 Marks]
✅ Step-by-Step Solution & Working
Solution:
• (b) Conversion: 1 kg = 1000 g, therefore 2 kg = 2 × 1000 g = 2,000 grams.
• (a) Weights needed: 2,000 g ÷ 500 g = 4 weights of 500 g.
• (b) Conversion: 1 kg = 1000 g, therefore 2 kg = 2 × 1000 g = 2,000 grams.
• (a) Weights needed: 2,000 g ÷ 500 g = 4 weights of 500 g.
CBSE Step-by-Step Marking Scheme
Correct conversion to 2000 g
1.0 M
Correct number of 500 g weights (4)
1.0 M
Q3
Equal Weight Comparison • Volume vs Mass
Which is heavier: 1 kg of iron or 1 kg of cotton wool? Explain why many people mistakenly think iron is heavier.
[3 Marks]
✅ Step-by-Step Solution & Working
Explanation:
• Answer: Both are equally heavy. Both weigh exactly 1 kilogram (1 kg = 1 kg).
• Reason for Common Mistake: Iron is dense and occupies a very small volume, whereas 1 kg of cotton is fluffy and occupies a huge bag. People confuse larger size or density with weight, but on a balance scale, both balance each other perfectly.
• Answer: Both are equally heavy. Both weigh exactly 1 kilogram (1 kg = 1 kg).
• Reason for Common Mistake: Iron is dense and occupies a very small volume, whereas 1 kg of cotton is fluffy and occupies a huge bag. People confuse larger size or density with weight, but on a balance scale, both balance each other perfectly.
CBSE Step-by-Step Marking Scheme
Clear assertion that both weigh the same (1 kg)
1.5 M
Scientific explanation distinguishing volume/density from mass
1.5 M
Q4
Gur and Groundnuts • Volume vs Weight
Shabnam bought 1 kg of jaggery (gur) and 1 kg of groundnuts in the market.
(a) Which is heavier: 1 kg of jaggery or 1 kg of groundnuts?
(b) Why does the bag of groundnuts look so much bigger than the bag of jaggery?
[3 Marks]
(a) Which is heavier: 1 kg of jaggery or 1 kg of groundnuts?
(b) Why does the bag of groundnuts look so much bigger than the bag of jaggery?
✅ Step-by-Step Solution & Working
Step-by-Step Physics & Math:
(a) Weight Comparison:
• Both weigh exactly the same (1 kg = 1 kg). Neither is heavier.
(b) Volume Difference:
• Groundnuts are light and hollow with air spaces inside their shells (low density), so 1 kg takes up a large space (volume).
• Jaggery is dense and solid (high density), so 1 kg occupies a small, compact volume.
(a) Weight Comparison:
• Both weigh exactly the same (1 kg = 1 kg). Neither is heavier.
(b) Volume Difference:
• Groundnuts are light and hollow with air spaces inside their shells (low density), so 1 kg takes up a large space (volume).
• Jaggery is dense and solid (high density), so 1 kg occupies a small, compact volume.
CBSE Step-by-Step Marking Scheme
Correct conclusion that both weigh equal (1 kg)
1.5 M
Scientific explanation of density and volume differences
1.5 M
Q5
Double Your Weight • Kunjamma's Parents Tradition
At Kunjamma's birth, her parents distributed sweets equal to double her weight. Kunjamma weighed 3 kg at birth.
(a) How many kilograms of sweets did they distribute at her birth?
(b) On her 4th birthday, Kunjamma weighed 15 kg. How many kilograms of sweets were distributed then?
[3 Marks]
(a) How many kilograms of sweets did they distribute at her birth?
(b) On her 4th birthday, Kunjamma weighed 15 kg. How many kilograms of sweets were distributed then?
✅ Step-by-Step Solution & Working
Step-by-Step Calculations:
(a) Sweets at Birth:
• Weight at birth = 3 kg.
• Double her weight = 2 × 3 kg = 6 kg of sweets.
(b) Sweets on 4th Birthday:
• Weight on 4th birthday = 15 kg.
• Double her weight = 2 × 15 kg = 30 kg of sweets.
(a) Sweets at Birth:
• Weight at birth = 3 kg.
• Double her weight = 2 × 3 kg = 6 kg of sweets.
(b) Sweets on 4th Birthday:
• Weight on 4th birthday = 15 kg.
• Double her weight = 2 × 15 kg = 30 kg of sweets.
CBSE Step-by-Step Marking Scheme
Correct calculation for birth (6 kg)
1.5 M
Correct calculation for 4th birthday (30 kg)
1.5 M
Q6
Balance Scale Estimation • Heavier or Lighter
Guess which object is heavier than 1 kg and which is lighter than 1 kg:
(a) Your school bag full of books.
(b) A geometry box compass.
(c) A brick.
(d) A pair of socks.
[4 Marks]
(a) Your school bag full of books.
(b) A geometry box compass.
(c) A brick.
(d) A pair of socks.
✅ Step-by-Step Solution & Working
Weight Estimation:
• (a) School bag full of books: Heavier than 1 kg (~3 to 5 kg).
• (b) Geometry box compass: Lighter than 1 kg (~50 grams).
• (c) A brick: Heavier than 1 kg (~2.5 to 3 kg).
• (d) A pair of socks: Lighter than 1 kg (~40 grams).
• (a) School bag full of books: Heavier than 1 kg (~3 to 5 kg).
• (b) Geometry box compass: Lighter than 1 kg (~50 grams).
• (c) A brick: Heavier than 1 kg (~2.5 to 3 kg).
• (d) A pair of socks: Lighter than 1 kg (~40 grams).
CBSE Step-by-Step Marking Scheme
Correct classifications for (a) and (b)
2.0 M
Correct classifications for (c) and (d)
2.0 M
Q7
Grocery Package Weights • Finding Total Weight
Ramesh bought from the supermarket:
• 2 kg of rice
• 500 g of dal
• 250 g of tea leaves
• 250 g of almonds
(a) Find the total weight of items bought in kilograms and grams.
(b) Is the total weight more than 3 kg or less than 3 kg?
[3 Marks]
• 2 kg of rice
• 500 g of dal
• 250 g of tea leaves
• 250 g of almonds
(a) Find the total weight of items bought in kilograms and grams.
(b) Is the total weight more than 3 kg or less than 3 kg?
✅ Step-by-Step Solution & Working
Step-by-Step Addition:
• Rice = 2 kg 000 g.
• Dal = 500 g.
• Tea leaves = 250 g.
• Almonds = 250 g.
• Grams total: 500 + 250 + 250 = 1000 g = 1 kg.
• Kilograms total: 2 kg + 1 kg = 3 kg 000 g (exactly 3 kg).
(b) Comparison:
• The total weight is exactly 3 kg (neither more nor less).
• Rice = 2 kg 000 g.
• Dal = 500 g.
• Tea leaves = 250 g.
• Almonds = 250 g.
• Grams total: 500 + 250 + 250 = 1000 g = 1 kg.
• Kilograms total: 2 kg + 1 kg = 3 kg 000 g (exactly 3 kg).
(b) Comparison:
• The total weight is exactly 3 kg (neither more nor less).
CBSE Step-by-Step Marking Scheme
Correct conversion and addition (3 kg 000 g)
2.0 M
Correct equality comparison
1.0 M
Q8
Textbook Exercise • Real-Life Math
In Chapter 8 ('Who Is Heavier?'), a student solves an NCERT word problem: If 1 kg of apples costs ₹60 and 1 kg of oranges costs ₹40, how much do 2 kg of apples and 3 kg of oranges cost altogether?
[3 Marks]
✅ Step-by-Step Solution & Working
Step-by-Step Solution:
1. Cost of 2 kg apples = 2 × ₹60 = ₹120.
2. Cost of 3 kg oranges = 3 × ₹40 = ₹120.
3. Total cost = ₹120 + ₹120 = ₹240.
1. Cost of 2 kg apples = 2 × ₹60 = ₹120.
2. Cost of 3 kg oranges = 3 × ₹40 = ₹120.
3. Total cost = ₹120 + ₹120 = ₹240.
CBSE Step-by-Step Marking Scheme
Apples = ₹120
1 M
Oranges = ₹120
1 M
Total = ₹240
1 M
Q9
In-Text Activity • Hands-on Investigation
In 'Who Is Heavier?', how do you measure and compare quantities accurately? Explain with an example using standard units.
[3 Marks]
✅ Step-by-Step Solution & Working
Measurement Explanation:
• Standard units provide consistent and reliable measurements across the world.
• For length, we use metres (m) and centimetres (cm).
• For weight, we use kilograms (kg) and grams (g).
• For liquids, we use litres (L) and millilitres (mL).
• Unlike non-standard units (such as footsteps or handspans), standard units give the exact same measurement no matter who measures.
• Standard units provide consistent and reliable measurements across the world.
• For length, we use metres (m) and centimetres (cm).
• For weight, we use kilograms (kg) and grams (g).
• For liquids, we use litres (L) and millilitres (mL).
• Unlike non-standard units (such as footsteps or handspans), standard units give the exact same measurement no matter who measures.
CBSE Step-by-Step Marking Scheme
Standard units defined
1.5 M
Examples for length, weight, liquid
1.5 M
Q10
Practice Time • Two-Step Word Problem
Suresh bought a school bag for ₹175 and a pencil box for ₹45. He gave a ₹500 note to the shopkeeper. How much change did he receive?
[3 Marks]
✅ Step-by-Step Solution & Working
Step-by-Step Solution:
1. Total money spent = ₹175 + ₹45 = ₹220.
2. Amount paid = ₹500.
3. Change returned = ₹500 - ₹220 = ₹280.
1. Total money spent = ₹175 + ₹45 = ₹220.
2. Amount paid = ₹500.
3. Change returned = ₹500 - ₹220 = ₹280.
CBSE Step-by-Step Marking Scheme
Total spent = ₹220
1.5 M
Change = ₹280
1.5 M
Q11
Mental Math • Quick Calculations
Calculate mentally without writing long columns:
(a) 250 + 150 = ?
(b) 500 - 180 = ?
(c) 4 × 25 = ?
(d) 100 ÷ 4 = ?
[2 Marks]
(a) 250 + 150 = ?
(b) 500 - 180 = ?
(c) 4 × 25 = ?
(d) 100 ÷ 4 = ?
✅ Step-by-Step Solution & Working
Mental Calculations:
• (a) 250 + 150 = 400.
• (b) 500 - 180 = 320.
• (c) 4 × 25 = 100.
• (d) 100 ÷ 4 = 25.
• (a) 250 + 150 = 400.
• (b) 500 - 180 = 320.
• (c) 4 × 25 = 100.
• (d) 100 ÷ 4 = 25.
CBSE Step-by-Step Marking Scheme
All 4 mental results correct
2 M
Q12
Geometry & Shapes • Edge and Corner Counting
Name a 3D solid shape that has:
(a) 6 flat square faces, 12 straight edges, and 8 corners.
(b) 1 curved surface and 2 flat circular faces.
(c) Only 1 curved surface and 0 corners.
[3 Marks]
(a) 6 flat square faces, 12 straight edges, and 8 corners.
(b) 1 curved surface and 2 flat circular faces.
(c) Only 1 curved surface and 0 corners.
✅ Step-by-Step Solution & Working
Solid Shapes:
• (a) 6 square faces, 12 edges, 8 corners: Cube.
• (b) 1 curved and 2 circular faces: Cylinder.
• (c) Only 1 curved surface, 0 corners: Sphere.
• (a) 6 square faces, 12 edges, 8 corners: Cube.
• (b) 1 curved and 2 circular faces: Cylinder.
• (c) Only 1 curved surface, 0 corners: Sphere.
CBSE Step-by-Step Marking Scheme
Cube
1 M
Cylinder
1 M
Sphere
1 M
Q13
Pattern Time • Sequences and Rules
Identify the rule and find the next two terms: 5, 10, 20, 40, ___, ___.
[2 Marks]
✅ Step-by-Step Solution & Working
Rule: Each term is multiplied by 2 (doubled).
• 40 × 2 = 80
• 80 × 2 = 160.
Next terms are 80, 160.
• 40 × 2 = 80
• 80 × 2 = 160.
Next terms are 80, 160.
CBSE Step-by-Step Marking Scheme
Next terms 80, 160
1 M
Rule: multiplying by 2
1 M
Q14
Time & Calendar • Date Calculation
Rohan's summer vacation starts on 15th May and ends on 30th June. How many total days of vacation does Rohan get? (Remember: May has 31 days).
[3 Marks]
✅ Step-by-Step Solution & Working
Days Count:
• Days in May: From 15th to 31st = (31 - 15) + 1 = 17 days.
• Days in June: Full 30 days = 30 days.
• Total vacation days = 17 + 30 = 47 days.
• Days in May: From 15th to 31st = (31 - 15) + 1 = 17 days.
• Days in June: Full 30 days = 30 days.
• Total vacation days = 17 + 30 = 47 days.
CBSE Step-by-Step Marking Scheme
May days = 17
1.5 M
June days = 30; Total = 47 days
1.5 M
Q15
Equal Sharing • Division Problem
Mother bakes 36 cookies and wants to distribute them equally among 4 children. How many cookies does each child receive? Write the division sentence.
[2 Marks]
✅ Step-by-Step Solution & Working
Equal Sharing:
• Total cookies = 36.
• Number of children = 4.
• Cookies per child = 36 ÷ 4 = 9 cookies.
• Division sentence: 36 ÷ 4 = 9.
• Total cookies = 36.
• Number of children = 4.
• Cookies per child = 36 ÷ 4 = 9 cookies.
• Division sentence: 36 ÷ 4 = 9.
CBSE Step-by-Step Marking Scheme
36 ÷ 4 = 9 cookies
2 M
Q16
Data Handling • Reading a Bar Chart
A survey of pets owned by children: Dog (14), Cat (10), Parrot (6), Fish (8).
(a) Which pet is owned by the least number of children?
(b) How many total pets are there?
(c) How many more dogs are there than parrots?
[3 Marks]
(a) Which pet is owned by the least number of children?
(b) How many total pets are there?
(c) How many more dogs are there than parrots?
✅ Step-by-Step Solution & Working
Survey Analysis:
• (a) Least owned pet: Parrot (only 6).
• (b) Total pets: 14 + 10 + 6 + 8 = 38 pets.
• (c) Difference: 14 Dogs - 6 Parrots = 8 more dogs.
• (a) Least owned pet: Parrot (only 6).
• (b) Total pets: 14 + 10 + 6 + 8 = 38 pets.
• (c) Difference: 14 Dogs - 6 Parrots = 8 more dogs.
CBSE Step-by-Step Marking Scheme
Parrot least
1 M
Total = 38
1 M
Difference = 8
1 M
Q17
Money • Making a Change
A toy train costs ₹85. You pay with a ₹100 note. The shopkeeper gives you change in 5-rupee coins only. How many 5-rupee coins do you receive?
[2 Marks]
✅ Step-by-Step Solution & Working
Calculations:
• Change due = ₹100 - ₹85 = ₹15.
• Number of 5-rupee coins = ₹15 ÷ ₹5 = 3 coins.
• Change due = ₹100 - ₹85 = ₹15.
• Number of 5-rupee coins = ₹15 ÷ ₹5 = 3 coins.
CBSE Step-by-Step Marking Scheme
Change = ₹15
1 M
3 coins of ₹5
1 M
🌟 NEP 2020 Competency-Based Case Study
School Sports Equipment Delivery
The sports department received a parcel containing 4 footballs (each weighing 400 g) and 2 cricket bats (each weighing 1 kg 200 g).
Analytical Task: What is the total weight of all the footballs? What is the combined total weight of all sports equipment in kilograms and grams?
Evaluation & Model Answer:
1. Total footballs weight = 4 × 400 g = 1,600 g = 1 kg 600 g.
2. Total cricket bats weight = 2 × (1 kg 200 g) = 2 kg 400 g.
3. Combined weight = (1 kg 600 g) + (2 kg 400 g) = 3 kg + 1000 g = 3 kg + 1 kg = 4 kilograms (4 kg).
2. Total cricket bats weight = 2 × (1 kg 200 g) = 2 kg 400 g.
3. Combined weight = (1 kg 600 g) + (2 kg 400 g) = 3 kg + 1000 g = 3 kg + 1 kg = 4 kilograms (4 kg).
Rubric: 1M footballs multiplication + 1M bats multiplication + 1M combined weight in kg.