ime: 2 Hours
Maximum Marks: 80
๐งพ General Instructions:
- All questions are compulsory
- Show proper steps wherever required
- Diagrams (number line) must be neat
๐ข Section A โ MCQs (1 ร 10 = 10 marks)
- The smallest whole number is:
a) 1 b) 0 c) -1 d) 10 - The successor of 999 is:
a) 998 b) 1000 c) 1001 d) 9999 - The predecessor of 1 is:
a) 0 b) -1 c) 1 d) Not possible - Which of the following is NOT a whole number?
a) 0 b) 5 c) -2 d) 10 - 5 + 3 = 3 + 5 shows:
a) Closure b) Commutative c) Associative d) Identity - 7 ร (2 + 3) = (7ร2) + (7ร3) shows:
a) Identity b) Closure c) Distributive d) Associative - Whole numbers are closed under:
a) Addition b) Subtraction c) Division d) All - 0 is the ______ identity:
a) Multiplicative b) Additive c) Both d) None - 1 is the ______ identity:
a) Additive b) Multiplicative c) Both d) None - The number line increases towards:
a) Left b) Right c) Both d) None
โ๏ธ Section B โ Short Answer (2 ร 10 = 20 marks)
- Write the successor of 45,678
- Write the predecessor of 10,000
- Write all whole numbers between 20 and 25
- Find: 99 ร 6 (using property)
- Check if subtraction is closed for whole numbers
- Identify the property: (3 + 5) + 2 = 3 + (5 + 2)
- Find: 25 ร (10 + 4)
- Write next three numbers after 9,999
- Why does 0 have no predecessor?
- Write the rule: 2, 4, 8, 16, ___
๐ง Section C โ Long Answer (4 ร 10 = 40 marks)
a) Explain commutative property with example
b) Is division commutative? Give reason
a) Solve using distributive property:
8 ร (15 + 5)
b) Explain why this method is useful
a) Represent 6 + 4 on number line
b) Represent 10 โ 7 on number line
a) Find pattern and next number:
1, 3, 6, 10, ___
b) Explain the pattern
a) Find: 999 ร 5 using shortcut
b) Explain the trick used
๐งฉ Section D โ Case-Based / Story-Based (5 ร 2 = 10 marks)
๐ฆ Case Study 1: Warehouse Storage
A warehouse stores 125 boxes, each containing 8 items.
- Find total number of items
- Solve using a smart method
๐ซ Case Study 2: School Attendance
A school has 1,000 students. On a particular day, 980 students were present.
- How many students were absent?
- Write predecessor of total students
๐ Case Study 3: Parking Area
A parking lot has 100 spaces in each section and 20 sections.
- Find total parking spaces
๐ฌ Case Study 4: Mall Visitors
A mall has 50 visitors per group and 18 groups.
- Find total visitors using distributive property
๐ Case Study 5: Library Growth
A library has 2,000 books and adds 20 books every month.
- How many books after 3 months?
๐ง Section E โ HOTS (5 ร 1 = 5 marks)
- Can a whole number have two successors?
- Why is subtraction not always possible in whole numbers?
- Find two consecutive numbers whose sum is 51
- Is there a largest whole number? Why?
- What happens when a smaller number is subtracted from a bigger number?
โ Answer Key
๐ข Section A โ MCQs
- b) 0
- b) 1000
- a) 0
- c) -2
- b) Commutative
- c) Distributive
- a) Addition
- b) Additive
- b) Multiplicative
- b) Right
โ๏ธ Section B โ Short Answers
- 45,679
- 9,999
- 21, 22, 23, 24
- 99 ร 6 = (100 ร 6 โ 6) = 594
- Not closed (e.g., 5 โ 9 = โ4, not a whole number)
- Associative Property
- 25 ร (10 + 4) = 25ร10 + 25ร4 = 250 + 100 = 350
- 10,000, 10,001, 10,002
- Because there is no whole number before 0
- Pattern: Multiply by 2 โ Next = 32
๐ง Section C โ Long Answers
a) Commutative property:
Example: 4 + 5 = 5 + 4
b) Division is NOT commutative
Example: 10 รท 2 โ 2 รท 10
a) 8 ร (15 + 5) = 8ร15 + 8ร5 = 120 + 40 = 160
b) It simplifies large calculations
a) 6 + 4 = 10 (move right 4 steps from 6)
b) 10 โ 7 = 3 (move left 7 steps from 10)
a) Next = 15
b) Pattern: Adding consecutive numbers (+2, +3, +4, +5โฆ)
a) 999 ร 5 = (1000 ร 5 โ 5) = 5000 โ 5 = 4995
b) Trick: Use (1000 โ 1) method
๐งฉ Section D โ Case-Based
- 125 ร 8 = 1000 items
- (100 ร 8) + (25 ร 8) = 800 + 200 = 1000
- 1000 โ 980 = 20 students
- Predecessor of 1000 = 999
- 100 ร 20 = 2000 spaces
- 50 ร 18 = 50ร10 + 50ร8 = 500 + 400 = 900 visitors
- 2000 + (20 ร 3) = 2000 + 60 = 2060 books
๐ง Section E โ HOTS
- โ No (every number has only one successor)
- Because result can be negative (not a whole number)
- Numbers: 25 and 26
- โ No, whole numbers are infinite
- Result remains a whole number (positive)
