Subtract Mixed Numbers with Unlike Denominators

Learn how to subtract mixed numbers when the denominators are different!

Understanding Mixed Number Subtraction

Mixed numbers are numbers that have both whole numbers and fractions.
When subtracting mixed numbers with different denominators, we need to find a common denominator first. This makes the fractions compatible so we can subtract them easily!

Step-by-Step Guide

1️⃣ Convert the mixed numbers to improper fractions

2️⃣ Find a common denominator for the fractions

3️⃣ Subtract the numerators and keep the denominator

4️⃣ Simplify the result if possible

5️⃣ Convert back to a mixed number if needed

Let's Practice Together!

Example 1: Subtract 2 3/4 - 1 1/2

1. Convert to improper fractions:

2 3/4 = 11/4 and 1 1/2 = 3/2

2. Find common denominator (4):

11/4 - 6/4 = 5/4

3. Convert back to mixed number:

5/4 = 1 1/4

Final answer: 1 1/4

Example 2: Subtract 3 2/5 - 1 3/4

1. Convert to improper fractions:

3 2/5 = 17/5 and 1 3/4 = 7/4

2. Find common denominator (20):

17/5 = 68/20 and 7/4 = 35/20

3. Subtract numerators:

68/20 - 35/20 = 33/20

4. Convert back to mixed number:

33/20 = 1 13/20

Final answer: 1 13/20

Parent Tips 🌟

  • Kitchen Math: Use measuring cups to demonstrate mixed numbers in real life - subtract 1½ cups from 2¾ cups of flour in a recipe.
  • Visual Aids: Draw pizzas or pies divided into different fractions to show why common denominators are needed.
  • Step Check: Have your child explain each step out loud - understanding why we convert to improper fractions is key!

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