Factors: Numbers that divide evenly into another number. For example, the factors of 18 are numbers that divide 18 without leaving a remainder.
- Start with 1 and the number itself
- Check each number up to the square root of the number
- If a number divides evenly, add both the divisor and the quotient
- List all unique factors
1×18=18, 2×9=18, 3×6=18
So factors are: 1, 2, 3, 6, 9, 18
Each factor represents a possible number of groups or cookies per group
1 group of 18 cookies, 2 groups of 9 cookies, 3 groups of 6 cookies, etc.
6 different ways: 1×18, 2×9, 3×6, 6×3, 9×2, 18×1
The grouping with the largest number as groups gives the most groups
18 groups of 1 cookie each gives the most groups (18 groups)
Emma can group her 18 cookies in 6 different ways:
1 group of 18, 2 groups of 9, 3 groups of 6, 6 groups of 3, 9 groups of 2, or 18 groups of 1
The grouping with the most groups is 18 groups of 1 cookie each.
• Factor identification: Find all numbers that divide 18 evenly
• Application: Each factor pair represents a possible grouping
• Optimization: The largest factor as number of groups gives the most groups
Least Common Multiple (LCM): The smallest positive number that is a multiple of two or more numbers.
Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54...
Multiples of 9: 9, 18, 27, 36, 45, 54, 63...
The smallest number that appears in both lists is 18
So LCM(6, 9) = 18
They will both arrive together again in 18 minutes
7:00 AM + 18 minutes = 7:18 AM
School bus: 18 ÷ 6 = 3 times (but we started at 0, so 3 additional arrivals)
City bus: 18 ÷ 9 = 2 times (but we started at 0, so 2 additional arrivals)
Total: School bus arrives 4 times (including 7:00), City bus arrives 3 times (including 7:00)
The buses will next arrive together at 7:18 AM.
By that time, the school bus will have arrived 4 times (at 7:00, 7:06, 7:12, 7:18) and the city bus will have arrived 3 times (at 7:00, 7:09, 7:18).
• LCM concept: Find the smallest common multiple of given numbers
• Time calculation: Add LCM minutes to the starting time
• Counting principle: Divide total time by interval to count occurrences
Arithmetic sequence: A sequence where each term increases by a constant amount called the common difference.
3 = 1×3, 6 = 2×3, 9 = 3×3, 12 = 4×3, 15 = 5×3
The nth term is 3n
Using the rule: 3(12) = 36
First 5 terms: 3, 6, 9, 12, 15
Sum = 3 + 6 + 9 + 12 + 15 = 45
The 12th number in the sequence is 36.
The first 5 figures require 45 triangles total.
• Pattern recognition: Identify the rule that generates the sequence
• Formula application: Use the rule to find any term in the sequence
• Series summation: Add consecutive terms to find totals
Rule: 3n
Factors: Numbers that divide evenly into another number
Multiples: Products of a number and any integer
Patterns: Sequences that follow a predictable rule
- Read carefully: Understand what the problem is asking
- Identify key words: Look for terms like "arrange," "together," "sequence," "pattern"
- Choose method: Determine if it's a factor, multiple, or pattern problem
- Solve systematically: Apply the appropriate mathematical operation
- Check answer: Verify your solution makes sense
Greatest Common Factor (GCF): The largest number that divides two or more numbers without leaving a remainder.
Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36
Common factors: 1, 2, 3, 4, 6, 12
Greatest common factor: 12
Crayons per kit: 24 ÷ 12 = 2
Colored pencils per kit: 36 ÷ 12 = 3
12 kits × 2 crayons = 24 crayons ✓
12 kits × 3 colored pencils = 36 colored pencils ✓
The teacher can make 12 identical art kits.
Each kit will contain 2 crayons and 3 colored pencils.
• GCF application: Use GCF to find maximum number of identical groups
• Division: Divide total items by group count to get items per group
• Verification: Multiply back to ensure original quantities are preserved
Linear pattern: A pattern where the number of elements increases by a constant amount each time.
Figure 1: 4 tiles, Figure 2: 9 tiles, Figure 3: 14 tiles
Each figure adds 5 tiles: 4, 4+5, 4+5+5, ...
Pattern rule: 5n - 1 (where n is the figure number)
Using the rule: 5(20) - 1 = 100 - 1 = 99 tiles
We already found that the 20th figure has 99 tiles
Let's verify: 5n - 1 = 99 → 5n = 100 → n = 20
Using the rule for n=1 to n=8:
Sum = Σ(5n-1) from n=1 to 8 = 5×Σn - 8 = 5×36 - 8 = 180 - 8 = 172
Or: 4+9+14+19+24+29+34+39 = 172
20th figure: 5(20) - 1 = 99 ✓
Figure with 99 tiles: n = 20 ✓
First 8 figures: 172 tiles ✓
The 20th figure will contain 99 tiles.
The 20th figure will contain exactly 99 tiles.
The first 8 figures contain 172 tiles combined.
• Pattern recognition: Identify the constant difference between terms
• Formula creation: Develop a rule based on the pattern
• Series summation: Use arithmetic series formulas to find totals
Rule: 5n - 1
Factor: A number that divides another number evenly
Multiple: The product of a number and an integer
Prime Number: A number with exactly two factors (1 and itself)
Composite Number: A number with more than two factors
- Understand: Read the problem carefully and identify what is being asked
- Plan: Decide which mathematical concept to apply (factors, multiples, or patterns)
- Solve: Apply the appropriate method systematically
- Check: Verify your answer makes sense in the context of the problem
• Factor pairs: If a×b = n, then a and b are factors of n
• Multiples: Multiples of n are n, 2n, 3n, 4n, ...
• GCF: Greatest common factor is the largest shared factor
• LCM: Least common multiple is the smallest shared multiple
• Pattern rule: Find the relationship between position and value
Sequence A: 2, 6, 10, 14, 18, ... (start at 2, add 4 each time)
Sequence B: 3, 9, 15, 21, 27, ... (start at 3, add 6 each time)
Sequence C: 1, 4, 9, 16, 25, ... (perfect squares)
Analysis: Different sequences follow different rules and grow at different rates.
- Sequence A: Arithmetic sequence (rule: 4n-2)
- Sequence B: Arithmetic sequence (rule: 6n-3)
- Sequence C: Perfect squares (rule: n²)