TEKS 5.3H: Add and Subtract Fractions
Add Fractions Using Models
About this lesson
Learning Target: I can add and subtract fractions with unlike denominators using models.
Focuses On:
- Adding fractions with unlike denominators using models
- Using fraction strips to determine common denominators
Builds On:
4.3E:
Represent and solve addition and subtraction of fractions with equal denominators using objects and pictorial models that build to the number line and properties of operations
4.3F:
Evaluate the reasonableness of sums and differences of fractions using benchmark fractions 0, 1/4, 1/2, 3/4, and 1, referring to the same whole
Next Level:
7.3A:
Add, subtract, multiply, and divide rational numbers fluently
Read More:
This lesson is designed to support student understanding of adding fractions. It builds on their 4th grade understanding of adding with like denominators and takes it to the next level to add with unlike denominators.
The two instructional blocks in this lesson are adding simple fractions and find common denominators.
In the first instructional block, students use models to support their understanding of common denominators. Students are asked to determine what fractions are represented by given models and to also use models to find common denominators before adding fractions.
The second instructional block has students adding fractions with unlike denominators without the use of models.
It is encouraged to show students where common denominators line up on the fraction models prior to showing the algorithm.
Grade 5MathTEKS 5.3HSubtract Fractions
About this lesson
Learning Target: I can represent and solve equations to subtract fractions.
Focuses On:
- Using models to support thinking to subtract fractions
- Determining a common denominator to subtract fractions
Builds On:
4.3E:
Represent and solve addition and subtraction of fractions with equal denominators using objects and pictorial models that build to the number line and properties of operations
4.3F:
Evaluate the reasonableness of sums and differences of fractions using benchmark fractions 0, 1/4, 1/2, 3/4, and 1, referring to the same whole
Next Level:
7.3A:
Add, subtract, multiply, and divide rational numbers fluently
Read More:
This lesson is designed to support student understanding of subtracting fractions. Intentional models that reflect assessment are built into the lesson. It is encouraged to explain where each piece of the model comes from and how a common denominator supports subtraction. Look for simple common denominators (quick multiples) before showing the algorithm.
The two instructional blocks in this lesson are subtracting simple fractions and find common denominators.
The first instructional block has students use models to support their understanding of common denominators. Students are asked to determine what fractions are represented by given models and to also use models to find common denominators before subtracting fractions.
The second instructional block has students subtracting fractions with unlike denominators without the use of models.
Scaffolds are built into each instructional block to further support students struggling to understand how to subtract fractions with unlike denominators.
Grade 5MathTEKS 5.3H