Grade 4 - Adding and Subtracting Fractions Unit
The Adding and Subtracting Fractions Unit involves using a variety of methods to join or separate fractional parts referring to the same whole. Methods may include replacing mixed numbers with equivalent fractions; using properties of operations and the relationship between addition and subtraction; and using visual models of fractions. Questions to answer may include:
- Why must we use the same whole when adding or subtracting fractional parts?
- How can a number line be used to represent adding or subtracting fractions?
- How can benchmark fractions help to determine whether a sum or difference makes sense?
Math Concepts and Skills:
The student understands fractions and uses them to solve problems.
The student:
- understands how a fraction (a/b) can be built by joining unit fractions (1/b) where a and b are whole numbers greater than zero, including when a > b.
- breaks fractions apart in more than one way into a sum of fractions with the same denominator and records results using words or symbols.
- represents and solves addition and subtraction of fractions with equal denominators.
- uses benchmark fractions to evaluate the reasonableness of sums and differences of fractions referring to the same whole.
Summative Assessment Task
Students determine how many muffins can be shared equally with nine friends if each friend gets 1 1/3 muffins.
Instructional Tasks/Formative Assessments
Students determine how many friends Jane can make celery sticks with peanut butter for.
Students determine what fractional piece of a raspberry pie is left after four pieces are eaten.
Students determine if Tessa has enough strong string to organize her recycling.
Students determine how many cups of popcorn kernels Mr. Morgan needs to pop to make popcorn for 50 students.
Students determine the height of a magic beanstalk.
Students determine if Anita and Carl both have the same amount of pizza left to eat.