Proper Fraction: A fraction where the numerator is less than the denominator (\(\frac{a}{b}\) where \(a < b\))
Improper Fraction: A fraction where the numerator is greater than or equal to the denominator (\(\frac{a}{b}\) where \(a ≥ b\))
Mixed Number: A number combining a whole number and a proper fraction (e.g., \(2\frac{3}{4}\))
Equivalent Fractions: Fractions that represent the same value but use different numerators and denominators
Unit Fraction: A fraction with numerator 1 (e.g., \(\frac{1}{5}\))
Like Fractions: Fractions with the same denominator
Unlike Fractions: Fractions with different denominators
Rule 1: When denominators are the same, compare numerators directly
Rule 2: When numerators are the same, compare denominators inversely
Rule 3: For unlike fractions, find common denominator or use cross multiplication
Rule 4: Any fraction greater than 1 is improper; less than 1 is proper
Rule 5: Equivalent fractions have equal cross products
Rule 6: To compare mixed numbers, compare whole numbers first, then fractional parts
Method 1 - Same Denominator: Compare numerators directly
Method 2 - Same Numerator: Compare denominators (inverse relationship)
Method 3 - Cross Multiplication: Multiply diagonally and compare products
Method 4 - Common Denominator: Convert to same denominator, then compare numerators
Method 5 - Decimal Conversion: Convert fractions to decimals and compare
Method 6 - Benchmark Comparison: Compare to known values like \(\frac{1}{2}\), \(\frac{1}{4}\), \(\frac{3}{4}\)
Simple: \(\frac{3}{5}\) vs \(\frac{2}{5}\) → Same denominator, 3 > 2, so \(\frac{3}{5} > \frac{2}{5}\)
Moderate: \(\frac{2}{3}\) vs \(\frac{2}{5}\) → Same numerator, 3 < 5, so \(\frac{2}{3} > \frac{2}{5}\)
Advanced: \(\frac{3}{4}\) vs \(\frac{5}{6}\) → Cross multiply: \(3 \times 6 = 18\), \(4 \times 5 = 20\), so \(\frac{5}{6} > \frac{3}{4}\)
Complex: \(\frac{7}{12}\) vs \(\frac{5}{8}\) → LCD = 24: \(\frac{14}{24}\) vs \(\frac{15}{24}\), so \(\frac{5}{8} > \frac{7}{12}\)
Very Complex: \(2\frac{3}{4}\) vs \(2\frac{5}{6}\) → Compare fractional parts: \(\frac{3}{4} = \frac{9}{12}\), \(\frac{5}{6} = \frac{10}{12}\), so \(2\frac{5}{6} > 2\frac{3}{4}\)
Tip 1: Always identify whether denominators or numerators are the same first
Tip 2: Remember: larger denominator = smaller fraction (when numerators are equal)
Tip 3: Use benchmarks like \(\frac{1}{2}\), \(\frac{1}{4}\), \(\frac{3}{4}\) to estimate
Tip 4: For mixed numbers, convert to improper fractions if easier to compare
Pitfall 1: Don't just compare numerators without considering denominators
Pitfall 2: Forgetting that \(\frac{4}{4} = 1\) and \(\frac{5}{4} > 1\)
Pitfall 3: Not simplifying fractions before comparing
Memory Aid: "More pieces, smaller pieces" - when denominator increases, each piece gets smaller
Formula: For \(\frac{a}{b}\) vs \(\frac{c}{d}\): if \(a \times d > b \times c\), then \(\frac{a}{b} > \frac{c}{d}\)
Pattern: Fractions increase as they approach 1 (from below) or decrease as they move away from 1
Verification: Always check your answer by converting to decimals or drawing models
Shortcut: If one fraction is clearly greater than 1 and the other is less than 1, the comparison is obvious
Mixed Numbers: Compare whole numbers first. If equal, compare fractional parts using fraction comparison rules.
Visual Model:
vs\(3\frac{5}{6}\) vs \(3\frac{7}{8}\)
- Compare whole numbers: 3 vs 3 → Equal
- Compare fractional parts: \(\frac{5}{6}\) vs \(\frac{7}{8}\)
- Use cross multiplication: \(5 \times 8 = 40\) vs \(6 \times 7 = 42\)
- Since 42 > 40, then \(\frac{7}{8} > \frac{5}{6}\)
Both have whole number 3, so they are equal
Now compare \(\frac{5}{6}\) vs \(\frac{7}{8}\)
\(5 \times 8 = 40\) and \(6 \times 7 = 42\)
40 vs 42 → 42 is greater than 40
Since \(\frac{7}{8} > \frac{5}{6}\), then \(3\frac{7}{8} > 3\frac{5}{6}\)
\(3\frac{7}{8}\) is greater than \(3\frac{5}{6}\)
• Mixed Number Comparison: Whole numbers first, then fractions
• Cross Multiplication: Compare fractional parts when whole numbers are equal
• Alternative Method: Convert to improper fractions: \(\frac{23}{6}\) vs \(\frac{31}{8}\)
Large Improper Fractions: Use cross multiplication or convert to mixed numbers for easier comparison.
Visual Model:
vs\(\frac{23}{12}\) vs \(\frac{19}{10}\)
- Use cross multiplication: \(23 \times 10 = 230\) vs \(12 \times 19 = 228\)
- Compare results: 230 vs 228
- Since 230 > 228, then \(\frac{23}{12} > \frac{19}{10}\)
\(23 \times 10 = 230\) and \(12 \times 19 = 228\)
230 vs 228 → 230 is greater than 228
Since \(23 \times 10 > 12 \times 19\), then \(\frac{23}{12} > \frac{19}{10}\)
Convert to mixed numbers: \(\frac{23}{12} = 1\frac{11}{12}\) and \(\frac{19}{10} = 1\frac{9}{10}\)
Compare fractional parts: \(\frac{11}{12}\) vs \(\frac{9}{10}\) → \(11 \times 10 = 110\), \(12 \times 9 = 108\)
Since \(110 > 108\), then \(\frac{11}{12} > \frac{9}{10}\), confirming \(\frac{23}{12} > \frac{19}{10}\)
\(\frac{23}{12}\) is greater than \(\frac{19}{10}\)
• Cross Multiplication: Works for any fractions regardless of size
• Improper Fraction Rule: Same comparison methods apply
• Alternative Method: Converting to mixed numbers can provide verification
Complex Fractions: Use LCD method or cross multiplication for accurate comparison of large denominators.
Visual Model:
vs\(\frac{17}{24}\) vs \(\frac{13}{18}\)
- Find LCD of 24 and 18 = 72
- Convert: \(\frac{17}{24} = \frac{51}{72}\) and \(\frac{13}{18} = \frac{52}{72}\)
- Compare numerators: 51 vs 52
- Since 52 > 51, then \(\frac{52}{72} > \frac{51}{72}\)
LCD of 24 and 18: Prime factorization: \(24 = 2^3 \times 3\), \(18 = 2 \times 3^2\)
LCD = \(2^3 \times 3^2 = 8 \times 9 = 72\)
\(\frac{17}{24} = \frac{17 \times 3}{24 \times 3} = \frac{51}{72}\)
\(\frac{13}{18} = \frac{13 \times 4}{18 \times 4} = \frac{52}{72}\)
51 vs 52 → 52 is greater than 51
Since denominators are the same, larger numerator means larger fraction
Cross multiply: \(17 \times 18 = 306\) vs \(24 \times 13 = 312\), confirming \(312 > 306\)
\(\frac{13}{18}\) is greater than \(\frac{17}{24}\)
• Common Denominator: Convert to same denominator for direct comparison
• Prime Factorization: Efficient method to find LCD
• Alternative Method: Cross multiplication provides verification
Advanced Equivalent Fractions: Two fractions are equivalent if their cross products are equal or if they simplify to the same fraction.
Visual Model:
=\(\frac{35}{42}\) vs \(\frac{45}{54}\) (both equal \(\frac{5}{6}\))
- Method 1: Cross multiply: \(35 \times 54 = 1890\) vs \(42 \times 45 = 1890\)
- Method 2: Simplify both fractions to lowest terms
- \(\frac{35}{42} = \frac{5}{6}\) and \(\frac{45}{54} = \frac{5}{6}\)
\(35 \times 54 = 1890\) and \(42 \times 45 = 1890\)
1890 vs 1890 → Products are equal
GCD of 35 and 42: Factors of 35: 1, 5, 7, 35; Factors of 42: 1, 2, 3, 6, 7, 14, 21, 42
GCD = 7: \(\frac{35 \div 7}{42 \div 7} = \frac{5}{6}\)
GCD of 45 and 54: Factors of 45: 1, 3, 5, 9, 15, 45; Factors of 54: 1, 2, 3, 6, 9, 18, 27, 54
GCD = 9: \(\frac{45 \div 9}{54 \div 9} = \frac{5}{6}\)
Both fractions simplify to \(\frac{5}{6}\), so they are equivalent
Yes, \(\frac{35}{42}\) and \(\frac{45}{54}\) are equivalent fractions
• Equivalence Test: Cross products must be equal
• Simplification: Reduce to lowest terms using GCD
• Verification: Both methods confirm equivalence
Advanced Ordering: Find a common denominator and compare numerators, or convert to decimals. For large denominators, consider using prime factorization to find LCD efficiently.
Number Line:
- Find LCD of denominators 4, 6, 9, 12 = 36 (using prime factorization)
- Convert each fraction to have denominator 36
- Compare numerators of converted fractions
- Order by increasing numerator values
4 = \(2^2\), 6 = \(2 \times 3\), 9 = \(3^2\), 12 = \(2^2 \times 3\)
LCD = \(2^2 \times 3^2 = 4 \times 9 = 36\)
\(\frac{3}{4} = \frac{27}{36}\), \(\frac{5}{6} = \frac{30}{36}\), \(\frac{7}{9} = \frac{28}{36}\), \(\frac{8}{9} = \frac{32}{36}\), \(\frac{11}{12} = \frac{33}{36}\)
27, 28, 30, 32, 33 → Order from least to greatest: 27, 28, 30, 32, 33
\(\frac{27}{36} < \frac{28}{36} < \frac{30}{36} < \frac{32}{36} < \frac{33}{36}\)
\(\frac{3}{4} < \frac{7}{9} < \frac{5}{6} < \frac{8}{9} < \frac{11}{12}\)
From least to greatest: \(\frac{3}{4}, \frac{7}{9}, \frac{5}{6}, \frac{8}{9}, \frac{11}{12}\)
• Common Denominator: Convert all fractions to same denominator
• Prime Factorization: Efficient method to find LCD for multiple fractions
• Verification: Convert to decimals to confirm order: 0.75, 0.778, 0.833, 0.889, 0.917