Add & Subtract Mixed Numbers with Unlike Denominators

Mixing it up with fractions!

What Are Mixed Numbers?

Mixed numbers are numbers that have both whole numbers and fractions!
Like having 2 whole pizzas and 3 slices of another pizza (where each pizza is cut into 8 slices). We'd write that as \(2\frac{3}{8}\).

How to Add/Subtract Mixed Numbers with Different Denominators

1️⃣ Find a common denominator - Make the bottom numbers the same

2️⃣ Convert the fractions - Change both fractions to use the common denominator

3️⃣ Add/Subtract - Do the math with the whole numbers and fractions separately

4️⃣ Simplify - Make your answer as simple as possible

Let's Practice Together!

Example 1: Adding Mixed Numbers

Solve: \(1\frac{1}{4} + 2\frac{1}{3}\)

Show Solution Steps
  1. Find common denominator: 4 and 3 → 12
  2. Convert fractions: \(\frac{1}{4} = \frac{3}{12}\) and \(\frac{1}{3} = \frac{4}{12}\)
  3. Add whole numbers: 1 + 2 = 3
  4. Add fractions: \(\frac{3}{12} + \frac{4}{12} = \frac{7}{12}\)
  5. Combine: \(3\frac{7}{12}\)

Example 2: Subtracting Mixed Numbers

Solve: \(3\frac{3}{5} - 1\frac{1}{2}\)

Show Solution Steps
  1. Find common denominator: 5 and 2 → 10
  2. Convert fractions: \(\frac{3}{5} = \frac{6}{10}\) and \(\frac{1}{2} = \frac{5}{10}\)
  3. Subtract whole numbers: 3 - 1 = 2
  4. Subtract fractions: \(\frac{6}{10} - \frac{5}{10} = \frac{1}{10}\)
  5. Combine: \(2\frac{1}{10}\)

Parent Tips 🌟

  • Use real-world examples like pizza slices or measuring cups to make the concept tangible.
  • Practice with baking - halving or doubling recipes provides perfect practice with fractions.
  • Make it a game - create fraction cards and have your child race to find common denominators.

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