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U04 • Lesson 22 of 105

Mixed Numbers & Improper Fractions

Introduces the relationship between mixed numbers and improper fractions. Students use visual models (fraction strips, number lines) to convert between the two forms, compare mixed numbers, and place them on a number line, building the foundation for fraction computation with values greater than one.

Upper Elementary • 3-5

Prerequisites: E06, M13

Key Concepts

  • converting improper fractions to mixed numbers
  • converting mixed numbers to improper fractions
  • comparing and ordering mixed numbers
  • placing mixed numbers on a number line

Mixed Numbers and Improper Fractions

You know that fractions like 3/4 represent parts of a whole. But what happens when you have more than one whole? You can write the amount as a mixed number (like 2 3/4) or as an improper fraction (like 11/4). These are just two different ways to write the same amount.

Key Vocabulary

TermDefinitionExample
Proper fractionNumerator is less than the denominator (less than 1 whole)3/4
Improper fractionNumerator is greater than or equal to the denominator (1 whole or more)11/4
Mixed numberA whole number plus a proper fraction2 3/4

Converting Improper Fractions to Mixed Numbers

Divide the numerator by the denominator. The quotient is the whole number, and the remainder becomes the new numerator.

Worked Example 1: Improper to Mixed

Convert 17/5 to a mixed number.

  1. Divide: 17 / 5 = 3 remainder 2.
  2. Whole number part: 3
  3. Fraction part: 2/5 (remainder over the original denominator)
17/5 = 3 2/5

Converting Mixed Numbers to Improper Fractions

Multiply the whole number by the denominator, add the numerator. Keep the same denominator.

Worked Example 2: Mixed to Improper

Convert 4 2/3 to an improper fraction.

  1. Multiply: 4 x 3 = 12
  2. Add the numerator: 12 + 2 = 14
  3. Keep the denominator: 3
4 2/3 = 14/3

Visualizing with Models

Imagine circles divided into equal slices. For 2 3/4:

Total slices: 4 + 4 + 3 = 11 slices, each one is a fourth, so 11/4.

Comparing Mixed Numbers

Worked Example 3: Comparing

Which is greater: 3 1/4 or 3 2/5?

  1. The whole number parts are both 3, so compare the fractions.
  2. Find a common denominator: 1/4 = 5/20 and 2/5 = 8/20.
  3. Since 5/20 < 8/20, we know 1/4 < 2/5.
3 1/4 < 3 2/5

Number Line Placement

To place 2 3/4 on a number line, find 2 and 3, then divide the space between them into 4 equal parts. Count 3 parts past 2. That is where 2 3/4 goes.

Common Mistake

When converting a mixed number to an improper fraction, students sometimes forget to add the numerator. Remember: multiply the whole number by the denominator, then add the numerator on top.

Practice Problems

1. Convert 23/6 to a mixed number.

Show Answer

23 / 6 = 3 remainder 5. So 23/6 = 3 5/6.

2. Convert 5 1/8 to an improper fraction.

Show Answer

5 x 8 = 40, plus 1 = 41. So 5 1/8 = 41/8.

3. Is 7/7 a proper fraction, improper fraction, or whole number?

Show Answer

7/7 = 1. It is an improper fraction equal to the whole number 1.

4. Which is greater: 2 5/6 or 2 3/4?

Show Answer

Same whole number (2). Compare fractions: 5/6 = 10/12 and 3/4 = 9/12. Since 10/12 > 9/12, 2 5/6 > 2 3/4.

5. Place 1 2/3 on a number line. Between which two whole numbers does it fall?

Show Answer

Between 1 and 2. Divide the space between 1 and 2 into 3 equal parts and mark the second line.

Lesson Summary

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