For fractions with different denominators, find common denominators before adding.
- Adding Like Fractions: Same denominator, add numerators
- Adding Unlike Fractions: Find common denominator first
- Adding Mixed Numbers: Add whole numbers and fractions separately
- Adding Tenths and Hundredths: Convert to common denominator
Like Fractions: Fractions with the same denominator
Both fractions have denominator 8
3 + 2 = 5
Result: 5/8
5/8 cannot be simplified (GCF of 5 and 8 is 1)
3/8 + 2/8 = 5/8
• Like denominators: Add numerators only
• Keep denominator: Don't change the common denominator
• Simplification: Check if fraction can be reduced
Unlike Fractions: Fractions with different denominators
LCM of 3 and 6 is 6
1/3 = 2/6 (multiply by 2/2)
1/6 stays as 1/6
2/6 + 1/6 = 3/6
3/6 = 1/2 (divide by GCF of 3)
1/3 + 1/6 = 1/2
• Common denominator: Find LCM of denominators
• Equivalent fractions: Convert to same denominator
• Simplification: Reduce to lowest terms
Mixed Numbers: Whole number combined with a fraction
2 + 1 = 3
1/4 + 3/4 = 4/4 = 1
3 + 1 = 4
Total = 4
2 1/4 + 1 3/4 = 4
• Separate addition: Add whole numbers and fractions separately
• Regrouping: Convert improper fraction to whole number if needed
• Combination: Add results together
Tenths and Hundredths: Convert to common denominator (hundredths)
3/10 = 30/100 (multiply by 10/10)
30/100 + 7/100 = 37/100
37/100 cannot be simplified
3/10 + 7/100 = 37/100
• Relationship: 1/10 = 10/100
• Conversion: Change to common denominator
• Equivalence: Multiply by 10/10 to convert tenths to hundredths
Word Problems: Translate words into mathematical operations
Lunch: 2/5, Dinner: 1/5
2/5 + 1/5 = 3/5
Sarah ate 3/5 of the pizza
3/5 is less than 1 whole pizza, which makes sense
Sarah ate 3/5 of the pizza in total
• Problem analysis: Identify relevant information
• Operation identification: Determine which operation to use
• Context interpretation: Answer in terms of the problem