Section 1
Finding a Common Denominator When One is a Multiple of the Other
Property
If one denominator, , is a multiple of another denominator, , then the larger denominator, , can be used as a common denominator.
In this Grade 5 enVision Mathematics lesson from Chapter 7, students learn how to find common denominators for fractions with unlike denominators by identifying multiples of each denominator and writing equivalent fractions. Students practice two methods: multiplying the denominators together and recognizing when one denominator is already a multiple of the other. This foundational skill prepares students to add and subtract fractions with unlike denominators throughout the chapter.
Section 1
Finding a Common Denominator When One is a Multiple of the Other
If one denominator, , is a multiple of another denominator, , then the larger denominator, , can be used as a common denominator.
Section 2
Finding Common Denominators with Area Models
A common denominator for two fractions, and , can be found visually using two identical area models.
By partitioning the first model (representing ) with horizontal lines and the second model (representing ) with vertical lines, both models are decomposed into equal parts.
Expand to review the lesson summary and core properties.
Section 1
Finding a Common Denominator When One is a Multiple of the Other
If one denominator, , is a multiple of another denominator, , then the larger denominator, , can be used as a common denominator.
Section 2
Finding Common Denominators with Area Models
A common denominator for two fractions, and , can be found visually using two identical area models.
By partitioning the first model (representing ) with horizontal lines and the second model (representing ) with vertical lines, both models are decomposed into equal parts.