Chapter 1 of 11
Chapter 1: A Day at the Beach
Counting in Groups, Pairs & Estimating Collections | CBSE Session 2026–27
Core Pedagogical Competencies & Concepts
- Counting objects by grouping into pairs (twos) and fives.
- Estimating quantities visually before counting exact amounts.
- Recognizing more, less, or equal collections of beach shells and pebbles.
All Textbook Exercises & In-Text Tasks (17 Questions)
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Q1
Textbook Exercise • Group Counting
Look at the starfish on the sand. There are 4 groups with 2 starfish in each group. How many starfish are there in total?
[2 Marks]
✅ Step-by-Step Solution & Working
Step-by-Step Solution:
• Number of groups = 4
• Starfish in each group = 2
• Total starfish = 2 + 2 + 2 + 2 = 8 starfish (or 4 × 2 = 8).
• Number of groups = 4
• Starfish in each group = 2
• Total starfish = 2 + 2 + 2 + 2 = 8 starfish (or 4 × 2 = 8).
CBSE Step-by-Step Marking Scheme
Correct addition/multiplication sentence
1 M
Final answer with unit (8 starfish)
1 M
Q2
Visual Estimation • Pairs
Rohit has 11 flip-flops (slippers). Can he make complete pairs without any slipper left over? Explain your answer.
[3 Marks]
✅ Step-by-Step Solution & Working
Answer:
• A pair requires 2 items.
• 11 = 2 + 2 + 2 + 2 + 2 + 1.
• Rohit makes 5 complete pairs and 1 slipper is left over. Therefore, 11 is an odd number and cannot form complete pairs.
• A pair requires 2 items.
• 11 = 2 + 2 + 2 + 2 + 2 + 1.
• Rohit makes 5 complete pairs and 1 slipper is left over. Therefore, 11 is an odd number and cannot form complete pairs.
CBSE Step-by-Step Marking Scheme
Division into pairs (5 pairs)
1.5 M
Identification of 1 remainder / odd number
1.5 M
Q3
Word Problem • Shells on the Beach
Aarav found 15 white shells and 9 brown shells on the beach. How many shells did he find in all? Which shells were more and by how many?
[3 Marks]
✅ Step-by-Step Solution & Working
Calculation:
1. White shells = 15
2. Brown shells = 9
3. Total shells = 15 + 9 = 24 shells.
4. Comparison: White shells (15) are more than Brown shells (9).
5. Difference = 15 - 9 = 6 more white shells.
1. White shells = 15
2. Brown shells = 9
3. Total shells = 15 + 9 = 24 shells.
4. Comparison: White shells (15) are more than Brown shells (9).
5. Difference = 15 - 9 = 6 more white shells.
CBSE Step-by-Step Marking Scheme
Total shells (15 + 9 = 24)
1.5 M
Comparison and difference (15 - 9 = 6)
1.5 M
Q4
Mental Math • Skip Counting
Complete the skip-counting chain: 2, 4, 6, __, __, 12, __, 16.
[2 Marks]
✅ Step-by-Step Solution & Working
Answer:
The rule is adding 2 each time:
2, 4, 6, 8, 10, 12, 14, 16.
The rule is adding 2 each time:
2, 4, 6, 8, 10, 12, 14, 16.
CBSE Step-by-Step Marking Scheme
Filled in 8, 10, 14 correctly
2 M
Q5
Let Us Do • Grouping by 5s
Riya collects 20 smooth pebbles and arranges them into groups of 5. How many groups of 5 does she make?
[2 Marks]
✅ Step-by-Step Solution & Working
Step-by-Step Solution:
• Total pebbles = 20
• Pebbles per group = 5
• 5 + 5 + 5 + 5 = 20 (4 groups of 5).
• Therefore, Riya makes 4 groups of 5 pebbles.
• Total pebbles = 20
• Pebbles per group = 5
• 5 + 5 + 5 + 5 = 20 (4 groups of 5).
• Therefore, Riya makes 4 groups of 5 pebbles.
CBSE Step-by-Step Marking Scheme
Grouping breakdown (5+5+5+5)
1 M
Final count: 4 groups
1 M
Q6
Let Us Do • Finger Counting
Each hand has 5 fingers. How many fingers do 4 children hold up in total?
[2 Marks]
✅ Step-by-Step Solution & Working
Calculation:
• Each child has 2 hands = 10 fingers.
• 4 children have = 10 + 10 + 10 + 10 = 40 fingers.
• (Alternatively: 4 children have 8 hands; 8 × 5 = 40 fingers).
• Each child has 2 hands = 10 fingers.
• 4 children have = 10 + 10 + 10 + 10 = 40 fingers.
• (Alternatively: 4 children have 8 hands; 8 × 5 = 40 fingers).
CBSE Step-by-Step Marking Scheme
Correct addition sentence
1 M
Final answer: 40 fingers
1 M
Q7
Estimation • More or Less
Look at the pile of coconuts under the palm tree without counting. Guess if there are more than 10 or less than 10 coconuts. If the count is 13, was the guess correct?
[2 Marks]
✅ Step-by-Step Solution & Working
Answer:
• Exact count = 13 coconuts.
• Since 13 is greater than 10 (13 > 10), there are more than 10 coconuts.
• If the guess was 'more than 10', the guess was correct.
• Exact count = 13 coconuts.
• Since 13 is greater than 10 (13 > 10), there are more than 10 coconuts.
• If the guess was 'more than 10', the guess was correct.
CBSE Step-by-Step Marking Scheme
Comparison (13 > 10)
1 M
Conclusion: More than 10
1 M
Q8
Let Us Think • Odd and Even Pairs
Can 16 children form pairs of 2 for a three-legged race without anyone being left alone? What about 17 children?
[3 Marks]
✅ Step-by-Step Solution & Working
Solution:
1. For 16 children: 16 ÷ 2 = 8 complete pairs (nobody is left alone because 16 is an even number).
2. For 17 children: 17 = 16 + 1 = 8 pairs and 1 child is left alone (17 is an odd number).
1. For 16 children: 16 ÷ 2 = 8 complete pairs (nobody is left alone because 16 is an even number).
2. For 17 children: 17 = 16 + 1 = 8 pairs and 1 child is left alone (17 is an odd number).
CBSE Step-by-Step Marking Scheme
16 children form 8 pairs
1.5 M
17 children leaves 1 child out
1.5 M
Q9
Textbook Activity • Crab Counting
A beach picture shows 3 red crabs on one rock and 3 red crabs on another rock. Write the addition sentence and multiplication sentence for the total crabs.
[2 Marks]
✅ Step-by-Step Solution & Working
Solution:
• Addition sentence: 3 + 3 = 6 crabs.
• Multiplication sentence: 2 × 3 = 6 crabs (2 groups of 3).
• Addition sentence: 3 + 3 = 6 crabs.
• Multiplication sentence: 2 × 3 = 6 crabs (2 groups of 3).
CBSE Step-by-Step Marking Scheme
Addition sentence (3 + 3 = 6)
1 M
Multiplication sentence (2 × 3 = 6)
1 M
Q10
Mental Math • Number Bonds
Find the missing number to make a group of 10: (a) 6 + __ = 10, (b) 2 + __ = 10, (c) 7 + __ = 10, (d) 5 + __ = 10.
[2 Marks]
✅ Step-by-Step Solution & Working
Answers:
• (a) 6 + 4 = 10
• (b) 2 + 8 = 10
• (c) 7 + 3 = 10
• (d) 5 + 5 = 10.
• (a) 6 + 4 = 10
• (b) 2 + 8 = 10
• (c) 7 + 3 = 10
• (d) 5 + 5 = 10.
CBSE Step-by-Step Marking Scheme
All 4 number bonds correct (0.5 M each)
2 M
Q11
Word Problem • Shell Pouch
Tanvi puts 2 sea shells in each small paper pouch. If she has 16 shells, how many pouches will she fill?
[2 Marks]
✅ Step-by-Step Solution & Working
Step-by-Step Solution:
• Total shells = 16
• Shells per pouch = 2
• Skip count by 2s up to 16: 2, 4, 6, 8, 10, 12, 14, 16 (8 times).
• Tanvi will fill 8 pouches.
• Total shells = 16
• Shells per pouch = 2
• Skip count by 2s up to 16: 2, 4, 6, 8, 10, 12, 14, 16 (8 times).
• Tanvi will fill 8 pouches.
CBSE Step-by-Step Marking Scheme
Method / Skip counting by 2
1 M
Final answer: 8 pouches
1 M
Q12
Let Us Do • Comparing Groups
Group A has 3 pairs of flip-flops. Group B has 2 groups of 4 flip-flops. Which group has more flip-flops?
[3 Marks]
✅ Step-by-Step Solution & Working
Calculation:
• Group A = 3 pairs = 3 × 2 = 6 flip-flops.
• Group B = 2 groups of 4 = 2 × 4 = 8 flip-flops.
• Since 8 > 6, Group B has more flip-flops.
• Group A = 3 pairs = 3 × 2 = 6 flip-flops.
• Group B = 2 groups of 4 = 2 × 4 = 8 flip-flops.
• Since 8 > 6, Group B has more flip-flops.
CBSE Step-by-Step Marking Scheme
Group A count = 6
1 M
Group B count = 8
1 M
Comparison: Group B has more
1 M
Q13
Skip Counting • Fives Chain
Count the total number of toes on 5 children's feet by skip-counting in 10s (each child has 10 toes).
[2 Marks]
✅ Step-by-Step Solution & Working
Solution:
• Skip counting by 10s: 10, 20, 30, 40, 50.
• 5 children have 50 toes altogether.
• Skip counting by 10s: 10, 20, 30, 40, 50.
• 5 children have 50 toes altogether.
CBSE Step-by-Step Marking Scheme
Skip counting pattern
1 M
Final answer: 50 toes
1 M
Q14
Visual Puzzle • Matching Pairs
There are 7 left socks and 8 right socks in a laundry basket. How many complete pairs of socks can be made? Which sock is extra?
[2 Marks]
✅ Step-by-Step Solution & Working
Answer:
• A complete pair needs 1 left sock and 1 right sock.
• With 7 left socks and 8 right socks, you can make 7 complete pairs.
• 1 right sock is left extra.
• A complete pair needs 1 left sock and 1 right sock.
• With 7 left socks and 8 right socks, you can make 7 complete pairs.
• 1 right sock is left extra.
CBSE Step-by-Step Marking Scheme
7 complete pairs
1 M
1 right sock extra
1 M
Q15
Let Us Think • Number Riddle
I am a number between 10 and 20. If you count me in pairs of 2, there is no remainder. If you count me in groups of 5, there is no remainder. What number am I?
[2 Marks]
✅ Step-by-Step Solution & Working
Answer:
• Multiples of 2 between 10 and 20: 12, 14, 16, 18.
• Multiples of 5 between 10 and 20: 15.
• The only multiple of both 2 and 5 (ending in 0) between 10 and 20 is none other than None between 10 and 20 strictly, but if inclusive: 10 or 20.
• For a number strictly between 10 and 20, 15 is odd. If the number is within 1 to 20, 20 (or 10) fits both groups.
• Multiples of 2 between 10 and 20: 12, 14, 16, 18.
• Multiples of 5 between 10 and 20: 15.
• The only multiple of both 2 and 5 (ending in 0) between 10 and 20 is none other than None between 10 and 20 strictly, but if inclusive: 10 or 20.
• For a number strictly between 10 and 20, 15 is odd. If the number is within 1 to 20, 20 (or 10) fits both groups.
CBSE Step-by-Step Marking Scheme
Analysis of conditions
1 M
Correct deduction
1 M
Q16
Summary Drill • True or False
Write True or False:
(a) A pair always means 3 objects.
(b) 14 is an even number because it can be divided into pairs with nothing left over.
[2 Marks]
(a) A pair always means 3 objects.
(b) 14 is an even number because it can be divided into pairs with nothing left over.
✅ Step-by-Step Solution & Working
Answers:
(a) False (A pair always means exactly 2 objects).
(b) True (14 = 7 pairs of 2).
(a) False (A pair always means exactly 2 objects).
(b) True (14 = 7 pairs of 2).
CBSE Step-by-Step Marking Scheme
(a) False with reason
1 M
(b) True with reason
1 M
Q17
Creative Math • Beach Drawing
Draw 3 groups of 3 beach balls. Write the repeated addition sentence and find the total.
[2 Marks]
✅ Step-by-Step Solution & Working
Solution:
• Group 1: 3 balls
• Group 2: 3 balls
• Group 3: 3 balls
• Repeated addition: 3 + 3 + 3 = 9 beach balls.
• (Multiplication: 3 × 3 = 9).
• Group 1: 3 balls
• Group 2: 3 balls
• Group 3: 3 balls
• Repeated addition: 3 + 3 + 3 = 9 beach balls.
• (Multiplication: 3 × 3 = 9).
CBSE Step-by-Step Marking Scheme
Correct grouping representation
1 M
Repeated addition 3+3+3 = 9
1 M
🌟 NEP 2020 Competency-Based Case Study
Seashell Collection Project
Meena collects 14 seashells on the shore. Her brother collects 18 seashells. Meena groups her shells into pairs of 2.
Analytical Task: How many pairs does Meena form? How many total seashells did both children collect altogether?
Evaluation & Model Answer:
1. Meena has 14 shells. Since 1 pair = 2 shells, 14 ÷ 2 = 7 pairs.
2. Total seashells = 14 + 18 = 32 seashells.
2. Total seashells = 14 + 18 = 32 seashells.
Rubric: 1.5 M for pairs calculation + 1.5 M for total sum