Lesson 2 Represent Unit Fraction Multiplication

    • Let’s write expressions to represent multiplication of unit fractions.

Warm-up Which One Doesn’t Belong: Diagrams

Which one doesn’t belong?

  1. Square, length and width, 1. Partitioned into 3 rows of 2 of the same size rectangles. 2 rectangles shaded light blue. 1 rectangle shaded dark blue.
  2. Diagram. Square, length and width, 1. Partitioned into 5 rows of 2 of the same size rectangles. 1 rectangle shaded.
  3. Diagram. Square. Length and width, 1. Partitioned horizontally into 6 of the same size rectangles. 1 rectangle shaded.
  4. Diagram. Square, length and width, 1. Partitioned vertically in half. Left half partitioned horizontally into 3 equal rectangles. 1 rectangle shaded.

Activity 1 Interpret Diagrams

  1. Show of the square. Shade of of the square. How much of the whole square is shaded?

    Square, length and width, 1. 

  2. Show of the square. Shade of of the square. How much of the whole square is shaded?

    Diagram. Square. Length and width, 1. 

  3. How are the diagrams the same and how are they different?

Activity 2 Write an Expression

Problem 1

Priya shaded part of a square.

Diagram. Square, length and width, 1. Partitioned into 2 rows of 5 of the same size rectangles. 1 rectangle shaded.

  1. Explain or show how the expression   represents the area of the shaded piece.

  2. Explain or show how the expression   represents the area of the shaded piece.

Problem 2

Square, length and width, 1. Partitioned into 5 rows of 3 of the same size rectangles. 1 rectangle shaded. 

  1. Write a multiplication expression to represent the area of the shaded piece. Be prepared to explain your reasoning.

  2. How much of the whole square is shaded?

Practice Problem

Problem 1

  1. Write an expression for how much of the square is shaded.

    Diagram, square. Length and width, 1. Partitioned into 5 rows of 4 of the same size rectangles. 1 rectangle shaded.

  2. Find the value of your expression.