Chapter 4 of 14
Chapter 4: Long and Short
Length Measurement, Centimetres (cm) & Metres (m), Ruler Usage & Height Charts | CBSE Session 2026–27
Core Pedagogical Competencies & Concepts
- Measuring length using non-standard units (fingers, hand spans) vs standard units.
- Using a 15 cm ruler correctly: starting from 0, not from 1.
- Understanding standard units: Centimetre (cm), Metre (m), and Kilometre (km).
- 1 Metre = 100 Centimetres (1 m = 100 cm); 1 Kilometre = 1000 Metres.
All Textbook Exercises & In-Text Tasks (17 Questions)
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Q1
Unit Selection • cm, m, or km
Which unit (cm, m, or km) is best suited to measure: (a) The length of a safety pin, (b) The height of a coconut tree, (c) The distance between Delhi and Agra, (d) The length of a 500-rupee currency note?
[2 Marks]
✅ Step-by-Step Solution & Working
Appropriate Units:
• (a) Safety pin: Centimetres (cm) (small object)
• (b) Coconut tree: Metres (m) (tall height)
• (c) Distance between Delhi and Agra: Kilometres (km) (intercity travel)
• (d) Currency note: Centimetres (cm) (approx 15 cm).
• (a) Safety pin: Centimetres (cm) (small object)
• (b) Coconut tree: Metres (m) (tall height)
• (c) Distance between Delhi and Agra: Kilometres (km) (intercity travel)
• (d) Currency note: Centimetres (cm) (approx 15 cm).
CBSE Step-by-Step Marking Scheme
Correct units for small objects (cm)
1.0 M
Correct units for tree (m) and intercity distance (km)
1.0 M
Q2
Ruler Measurement Error Analysis
Rohan broke his ruler. The scale now starts from 3 cm instead of 0. If he places a wooden crayon with its left tip at 3 cm and the right tip reaches 11 cm, what is the actual length of the crayon?
[2 Marks]
✅ Step-by-Step Solution & Working
Calculation:
• Starting point = 3 cm
• Ending point = 11 cm
• Actual length = Ending point - Starting point = 11 cm - 3 cm = 8 cm.
• Starting point = 3 cm
• Ending point = 11 cm
• Actual length = Ending point - Starting point = 11 cm - 3 cm = 8 cm.
CBSE Step-by-Step Marking Scheme
Recognizing subtraction of starting offset
1.0 M
Correct calculation (11 - 3 = 8 cm)
1.0 M
Q3
Height Chart Comparison • Word Problem
In Class 3, Amit's height is 1 metre 25 centimetres. Sanya is 18 cm taller than Amit. What is Sanya's height in metres and centimetres?
[2 Marks]
✅ Step-by-Step Solution & Working
Solution:
• Amit's height = 1 m 25 cm
• Sanya's additional height = 18 cm
• Sanya's height = 1 m + (25 cm + 18 cm)
• 25 + 18 = 43 cm
• Sanya's total height = 1 metre 43 centimetres (1 m 43 cm).
• Amit's height = 1 m 25 cm
• Sanya's additional height = 18 cm
• Sanya's height = 1 m + (25 cm + 18 cm)
• 25 + 18 = 43 cm
• Sanya's total height = 1 metre 43 centimetres (1 m 43 cm).
CBSE Step-by-Step Marking Scheme
Correct addition of centimetre values (25 + 18 = 43)
1.0 M
Clear final representation in m and cm
1.0 M
Q4
Measurement Units • Centimetre vs Metre
Which unit will you use to measure the following: Centimetre (cm) or Metre (m)?
(a) Length of a pencil.
(b) Height of a sugarcane plant.
(c) Width of your fingernail.
(d) Distance between two lampposts on a road.
[4 Marks]
(a) Length of a pencil.
(b) Height of a sugarcane plant.
(c) Width of your fingernail.
(d) Distance between two lampposts on a road.
✅ Step-by-Step Solution & Working
Appropriate Units:
• (a) Length of a pencil: Centimetre (cm).
• (b) Height of a sugarcane plant: Metre (m).
• (c) Width of your fingernail: Centimetre (cm) (or millimetre).
• (d) Distance between two lampposts: Metre (m).
• (a) Length of a pencil: Centimetre (cm).
• (b) Height of a sugarcane plant: Metre (m).
• (c) Width of your fingernail: Centimetre (cm) (or millimetre).
• (d) Distance between two lampposts: Metre (m).
CBSE Step-by-Step Marking Scheme
Correct units for (a) and (b)
2.0 M
Correct units for (c) and (d)
2.0 M
Q5
Lali's Rope Measurement • Non-Standard Units
In the story, a farmer comes to Lali to buy 7 arms of rope. Lali measures the rope with her small arm.
(a) Why was the rope short when the farmer measured it with his own arm?
(b) What should the farmer do to get the right length using non-standard units?
(c) Why do we use standard rulers instead of arm-spans?
[3 Marks]
(a) Why was the rope short when the farmer measured it with his own arm?
(b) What should the farmer do to get the right length using non-standard units?
(c) Why do we use standard rulers instead of arm-spans?
✅ Step-by-Step Solution & Working
Step-by-Step Explanation:
(a) Reason:
• The farmer is an adult and has a much longer arm than young Lali. 7 arms of Lali's length is shorter than 7 arms of the farmer's length.
(b) Solution with Non-Standard Unit:
• The farmer should measure the rope using his own arm, or measure 7 times his own arm-span.
(c) Need for Standard Rulers:
• Standard units like metres and centimetres do not change from person to person. A 1-metre ruler is exactly the same length worldwide, ensuring fairness in trade.
(a) Reason:
• The farmer is an adult and has a much longer arm than young Lali. 7 arms of Lali's length is shorter than 7 arms of the farmer's length.
(b) Solution with Non-Standard Unit:
• The farmer should measure the rope using his own arm, or measure 7 times his own arm-span.
(c) Need for Standard Rulers:
• Standard units like metres and centimetres do not change from person to person. A 1-metre ruler is exactly the same length worldwide, ensuring fairness in trade.
CBSE Step-by-Step Marking Scheme
Explanation of arm length difference between adult and child
1.0 M
Correct solution for farmer measuring himself
1.0 M
Need for universal standard units (m, cm)
1.0 M
Q6
Ruler Measurement • Reading cm Scales
Look at a standard 15 cm plastic ruler:
(a) An eraser starts at mark 2 cm and ends at mark 7 cm. What is the length of the eraser?
(b) A leaf starts at mark 4 cm and ends at mark 12 cm. What is the length of the leaf?
[3 Marks]
(a) An eraser starts at mark 2 cm and ends at mark 7 cm. What is the length of the eraser?
(b) A leaf starts at mark 4 cm and ends at mark 12 cm. What is the length of the leaf?
✅ Step-by-Step Solution & Working
Step-by-Step Calculations:
(a) Eraser Length:
• End mark - Start mark = 7 cm - 2 cm = 5 cm.
(b) Leaf Length:
• End mark - Start mark = 12 cm - 4 cm = 8 cm.
(a) Eraser Length:
• End mark - Start mark = 7 cm - 2 cm = 5 cm.
(b) Leaf Length:
• End mark - Start mark = 12 cm - 4 cm = 8 cm.
CBSE Step-by-Step Marking Scheme
Correct calculation for eraser (7 - 2 = 5 cm)
1.5 M
Correct calculation for leaf (12 - 4 = 8 cm)
1.5 M
Q7
Unit Conversions • Metres and Centimetres
Convert the following measurements:
(a) 4 m into centimetres.
(b) 2 m 75 cm into centimetres.
(c) 350 cm into metres and centimetres.
[3 Marks]
(a) 4 m into centimetres.
(b) 2 m 75 cm into centimetres.
(c) 350 cm into metres and centimetres.
✅ Step-by-Step Solution & Working
Conversions (1 m = 100 cm):
• (a) 4 m: 4 × 100 = 400 cm.
• (b) 2 m 75 cm: (2 × 100) + 75 = 200 + 75 = 275 cm.
• (c) 350 cm: 300 cm + 50 cm = 3 m 50 cm.
• (a) 4 m: 4 × 100 = 400 cm.
• (b) 2 m 75 cm: (2 × 100) + 75 = 200 + 75 = 275 cm.
• (c) 350 cm: 300 cm + 50 cm = 3 m 50 cm.
CBSE Step-by-Step Marking Scheme
Correct answer for (a): 400 cm
1.0 M
Correct answer for (b): 275 cm
1.0 M
Correct answer for (c): 3 m 50 cm
1.0 M
Q8
Textbook Exercise • Real-Life Math
In Chapter 4 ('Long and Short'), 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 'Long and Short', 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
Inter-School Long Jump Competition
In the primary sports day long jump final, Danish jumped 2 metres 80 centimetres. Gurjeet jumped 15 cm less than Danish, while Rehana jumped 35 cm more than Danish.
Analytical Task: How far did Gurjeet jump? How far did Rehana jump? Did Rehana cross the 3-metre mark?
Evaluation & Model Answer:
1. Danish = 2 m 80 cm.
2. Gurjeet = 2 m 80 cm - 15 cm = 2 metres 65 centimetres.
3. Rehana = 2 m 80 cm + 35 cm = 2 m + 115 cm = 2 m + 1 m 15 cm = 3 metres 15 centimetres.
4. Since 3 m 15 cm > 3 m, yes, Rehana crossed the 3-metre mark.
2. Gurjeet = 2 m 80 cm - 15 cm = 2 metres 65 centimetres.
3. Rehana = 2 m 80 cm + 35 cm = 2 m + 115 cm = 2 m + 1 m 15 cm = 3 metres 15 centimetres.
4. Since 3 m 15 cm > 3 m, yes, Rehana crossed the 3-metre mark.
Rubric: 1M Gurjeet calculation + 1M Rehana calculation + 1M 3m threshold check.