Lesson 8 Add and Subtract Fractions

    • Let’s add and subtract fractions.

Warm-up Which One Doesn’t Belong: Fraction Representations

Which one doesn’t belong?

  1. Diagram. Two rectangles of equal length. Top rectangle split into 3 equal parts. 2 parts shaded. Bottom rectangle split into 6 equal parts. 4 shaded
  2. Two number lines of equal length.
  3. Diagram. Two rectangles of equal length.
  4. Number line. From 0 to 6 sixths. Evenly spaced by sixths. 

Activity 1 Card Sort: Fraction Sums and Differences

Your teacher will give you a set of cards that show expressions.

  1. Sort the cards into 2 categories of your choosing. Be prepared to explain the meaning of your categories.

  2. Sort the cards into 2 categories in a different way. Be prepared to explain the meaning of your new categories.

Activity 2 Add and Subtract

Find the value of each expression. Explain or show your thinking.

Practice Problem

Problem 1

Find the value of each sum. Explain or show your reasoning.

  3. How were the calculations the same? How were they different?