Lesson 3: Dividing Unit Fractions by Whole Numbers

Getting Started

Imagine that you have 1/2 of a pie and you want to share it with 2 friends. How much pie will each of you get to have? As you think about this, keep in mind that the 1/2 pie is the dividend because it is being divided, or split, into smaller parts. The number of people sharing the pie, in this case 3, is the divisor because it tells how many smaller parts there will be. So, the problem looks like this: 1/2 ÷ 3.

During this lesson, you're going to learn how to find quotients when dividing a unit fraction by a whole number. Keep in mind that a unit fraction is a fraction that has a numerator of 1, such as 1/2, 1/3, or 1/10.

Stuff You Need

  • card stock (kit)
  • colored pencils
  • glue or glue stick
  • Interactive Notebook
  • ruler (kit)
  • scissors

Ideas to Think About

  • How can we divide whole numbers and unit fractions?

Things to Know

  • Unit fraction: a fraction that has a numerator of 1
  • Algorithm: sequence of steps to follow when completing a math operation
  • The reciprocal of any fraction is when the numerator and the denominator are flipped. For example, the reciprocal of 2/1 is 1/2.
  • To divide a unit fraction by a whole number, you keep the first fraction, switch the division sign to a multiplication sign, flip the second fraction (to create its reciprocal), and then solve the problem.

Skills

  • Apply and extend previous understandings of division to divide unit fractions by whole numbers and whole numbers by unit fractions
  • Interpret division of a unit fraction by a non-zero whole number, and compute such quotients
  • Solve real world problems involving division of unit fractions by non-zero whole numbers and division of whole numbers by unit fractions by using visual fraction models and equations to represent the problem

Introducing the Lesson

During this lesson, your child is going to learn how to find quotients when dividing a unit fraction by a whole number. He should recall that a unit fraction is a fraction that has a numerator of 1. For example, 1/2, 1/3, and 1/10 are all unit fractions.