Learn on PengienVision, Mathematics, Grade 4Chapter 9: Understand Addition and Subtraction of Fractions

Lesson 9: Subtract Mixed Numbers

Grade 4 students learn how to subtract mixed numbers with like denominators using two strategies: renaming the minuend by borrowing a whole (converting it to an equivalent mixed number) and converting mixed numbers to improper fractions before subtracting. This lesson is part of Chapter 9 in enVision Mathematics Grade 4 and builds on students' understanding of equivalent fractions and the relationship between addition and subtraction.

Section 1

Procedure: Subtracting Mixed Numbers with Regrouping

Property

To subtract mixed numbers when the top fraction is smaller than the bottom fraction:

  1. Regroup: Take one from the whole number part of the first mixed number. Add that one to its fraction part by converting it to a fraction with the common denominator (e.g., 1=nn1 = \frac{n}{n}).
  2. Subtract Fractions: Subtract the fraction parts.
  3. Subtract Whole Numbers: Subtract the whole number parts.
  4. Simplify: Write the final answer in simplest form.

Examples

Section 2

Subtract by converting to improper fractions

Property

Subtract mixed numbers with common denominators as improper fractions.

Step 1. Rewrite the mixed numbers as improper fractions.

Step 2. Subtract the numerators.

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Procedure: Subtracting Mixed Numbers with Regrouping

Property

To subtract mixed numbers when the top fraction is smaller than the bottom fraction:

  1. Regroup: Take one from the whole number part of the first mixed number. Add that one to its fraction part by converting it to a fraction with the common denominator (e.g., 1=nn1 = \frac{n}{n}).
  2. Subtract Fractions: Subtract the fraction parts.
  3. Subtract Whole Numbers: Subtract the whole number parts.
  4. Simplify: Write the final answer in simplest form.

Examples

Section 2

Subtract by converting to improper fractions

Property

Subtract mixed numbers with common denominators as improper fractions.

Step 1. Rewrite the mixed numbers as improper fractions.

Step 2. Subtract the numerators.