Equal Arrangement: Using factors to determine possible rectangular arrangements
Static Problem: A problem with fixed parameters that doesn't change over time
- Find all factors of the total number
- Form factor pairs (rows × columns)
- Identify practical arrangements
- Evaluate for real-world constraints
Start with 1: 1 × 36 = 36 → Factors: 1, 36
Try 2: 2 × 18 = 36 → Factors: 2, 18
Try 3: 3 × 12 = 36 → Factors: 3, 12
Try 4: 4 × 9 = 36 → Factors: 4, 9
Try 6: 6 × 6 = 36 → Factors: 6
Try 7: 7 doesn't divide 36 evenly
Stop when factors repeat
All factors: {1, 2, 3, 4, 6, 9, 12, 18, 36}
1 row × 36 columns
2 rows × 18 columns
3 rows × 12 columns
4 rows × 9 columns
6 rows × 6 columns
9 rows × 4 columns
12 rows × 3 columns
18 rows × 2 columns
36 rows × 1 column
1 row × 36 columns: Too wide for classroom
2 rows × 18 columns: Very wide, impractical
3 rows × 12 columns: Quite wide
4 rows × 9 columns: Good balance
6 rows × 6 columns: Square arrangement, good
9 rows × 4 columns: Tall but narrow, good
12 rows × 3 columns: Very tall
18 rows × 2 columns: Extremely tall
36 rows × 1 column: Impractical
Best options: 4 rows × 9 columns or 6 rows × 6 columns
4 rows × 9 columns: Good visibility for all students
6 rows × 6 columns: Square, compact arrangement
Most practical: 4×9 or 6×6
Factors: {1,2,3,4,6,9,12,18,36}
Mrs. Johnson has 9 possible arrangements:
• 1 row × 36 columns
• 2 rows × 18 columns
• 3 rows × 12 columns
• 4 rows × 9 columns (recommended)
• 6 rows × 6 columns (recommended)
• 9 rows × 4 columns
• 12 rows × 3 columns
• 18 rows × 2 columns
• 36 rows × 1 column
The most practical arrangements are 4 rows × 9 columns or 6 rows × 6 columns.
• Factor Pairs: Each pair represents a possible arrangement
• Real-world Application: Factors relate to arranging objects
• Practical Constraints: Consider classroom limitations
Least Common Multiple (LCM): The smallest number that is a multiple of two or more numbers
Synchronized Events: Using LCM to find when periodic events coincide
12 = 4 × 3 = 2² × 3
18 = 9 × 2 = 3² × 2
12 = 2² × 3¹
18 = 2¹ × 3²
LCM = 2² × 3² = 4 × 9 = 36
Bus A: 36 ÷ 12 = 3 trips
Bus B: 36 ÷ 18 = 2 trips
Bus A returns at: 12, 24, 36 minutes
Bus B returns at: 18, 36 minutes
Both return together at: 36 minutes ✓
Bus A: 3 trips
Bus B: 2 trips
Both buses will return to the station at the same time after 36 minutes.
By that time:
• Bus A will have made 3 complete trips
• Bus B will have made 2 complete trips
This is a classic application of LCM in scheduling and timing.
• LCM Rule: For synchronized events, use LCM of intervals
• Prime Factorization: Efficient method for finding LCM
• Division Rule: Number of cycles = Total time ÷ Cycle time
Static Problem: A mathematical problem with fixed parameters that don't change over time or context
Factor: A number that divides another number evenly with no remainder
Multiple: The product of a number and any integer
Least Common Multiple (LCM): The smallest positive integer that is divisible by two or more numbers
Greatest Common Divisor (GCD): The largest positive integer that divides two or more numbers without remainder
- Identify Fixed Parameters: Recognize what doesn't change
- Find Relevant Concepts: Determine if factors, multiples, or patterns apply
- Apply Systematic Methods: Use factorization, LCM, or GCD as appropriate
- Verify Solutions: Check that answers satisfy all conditions
• Identify all fixed parameters first
• Determine if the problem involves factors, multiples, or patterns
• Use systematic approaches to find all possibilities
• Consider practical constraints when applicable
• Verify solutions against original problem conditions
Optimization: Finding the best solution among all possible arrangements
1 × 60 = 60
2 × 30 = 60
3 × 20 = 60
4 × 15 = 60
5 × 12 = 60
6 × 10 = 60
Stop at √60 ≈ 7.7 (after 6×10)
3 rows × 20 bulbs per row
4 rows × 15 bulbs per row
5 rows × 12 bulbs per row
6 rows × 10 bulbs per row
3 rows: 20 bulbs per row
4 rows: 15 bulbs per row
5 rows: 12 bulbs per row
6 rows: 10 bulbs per row
Highest: 20 bulbs per row with 3 rows
3 rows × 20 bulbs: Long, narrow garden
4 rows × 15 bulbs: Good balance
5 rows × 12 bulbs: Good balance
6 rows × 10 bulbs: Compact, square-like
Optimal: 6 rows × 10 bulbs (most compact arrangement)
Maximum bulbs per row: 20 (with 3 rows)
Recommended: 6 rows × 10 bulbs
The optimal arrangement is 6 rows with 10 bulbs per row.
While maximizing bulbs per row would mean 3 rows with 20 bulbs each, the most balanced and practical arrangement is 6 rows with 10 bulbs per row.
This creates a more square-like garden that's easier to maintain.
• Optimization: Balance mathematical maximum with practical considerations
• Constraint Satisfaction: Meet all specified requirements
• Practical Evaluation: Consider real-world implications
Prime Number: A number greater than 1 with exactly two factors: 1 and itself
Border Pattern: Using perimeter constraints in geometric arrangements
48 tiles total in a rectangle
Border of rectangle uses prime numbers of tiles on each side
Need to determine if this is possible
1 × 48 = 48
2 × 24 = 48
3 × 16 = 48
4 × 12 = 48
6 × 8 = 48
Rectangle 1×48: Dimensions are 1 and 48 (1 is not prime)
Rectangle 2×24: Dimensions are 2 and 24 (2 is prime, 24 is not)
Rectangle 3×16: Dimensions are 3 and 16 (3 is prime, 16 is not)
Rectangle 4×12: Dimensions are 4 and 12 (neither is prime)
Rectangle 6×8: Dimensions are 6 and 8 (neither is prime)
If perimeter must be prime: Perimeter = 2(length + width)
For 6×8: Perimeter = 2(6+8) = 28 (not prime)
For 4×12: Perimeter = 2(4+12) = 32 (not prime)
For 3×16: Perimeter = 2(3+16) = 38 (not prime)
For 2×24: Perimeter = 2(2+24) = 52 (not prime)
For 1×48: Perimeter = 2(1+48) = 98 (not prime)
No rectangle with area 48 has both dimensions as prime numbers
No rectangle with area 48 has a prime perimeter
It's impossible to create such a design with 48 tiles
Reason: No factor pair uses two primes
Alternative: Use 15 tiles (3×5)
No, it's not possible to create a rectangular tile pattern using 48 tiles with prime numbers of tiles on each side.
The factor pairs of 48 are: (1,48), (2,24), (3,16), (4,12), (6,8).
In no case do both numbers in the pair represent prime numbers.
For such a design to work, you'd need a number that is the product of two primes.
• Prime Testing: Verify if numbers are prime
• Systematic Analysis: Check all possibilities
• Impossibility Proof: Demonstrate why no solution exists
Static Problem: A mathematical problem with fixed parameters that remain constant throughout the problem
Factor: A number that divides another number evenly with no remainder
Multiple: The product of a number and any integer
Least Common Multiple (LCM): The smallest positive integer divisible by two or more numbers
Greatest Common Divisor (GCD): The largest positive integer that divides two or more numbers without remainder
- Parameter Identification: Recognize all fixed values
- Concept Matching: Determine if factors, multiples, or patterns apply
- Systematic Enumeration: Find all possible solutions
- Constraint Application: Apply any additional requirements
- Solution Verification: Check all conditions are met
• Identify all fixed parameters before solving
• Use systematic approaches to enumerate all possibilities
• Apply mathematical concepts appropriately (factors, multiples, patterns)
• Consider practical constraints and real-world applicability
• Verify solutions against original problem requirements
• Explain impossibility when no solution exists
Key Characteristics:
- Fixed, unchanging parameters
- No time-dependent variables
- Complete information provided upfront
- Solutions don't change over time
- Focus on mathematical relationships
Static problems build foundational problem-solving skills!