Lesson 14 Story Problems and Equations

    • Let’s make sense of equations and solve story problems.

Warm-up Which One Doesn’t Belong: Diagrams

Which one doesn’t belong?

  1. Diagram. One rectangle partitioned into two parts. First part, total length, 13. Second part, total length, question mark. Total length of rectangle, 40.
  2. Diagram. One rectangle partitioned into 2 parts. One part, total length 27. Other part, total length 13. Total length of rectangle, question mark.

  4. Diagram. Two rectangles of equal length. Top rectangle partitioned into two parts. First part, shaded, total length 27. Second part has a dashed outline, total length question mark. Bottom rectangle, shaded, total length, 40.

Activity 1 Card Sort: Story Problems and Equations

  1. Match each story problem with an equation. Explain why the cards match.

  2. Choose 2 story problems and solve them. Show your thinking.

Activity 2 Represent and Solve Story Problems

Problem 1

Diagram. One rectangle partitioned into two parts. First part, labeled seeds at start, total length, question mark. Second part, labeled, seeds won, total length, 36. Total length of rectangle, 64.

Lin played a game with seeds. She started the game with some seeds. Then she won 36 seeds. Now she has 64 seeds. How many seeds did Lin have at first?

  1. Write an equation using a question mark for the unknown value.

  2. Solve. Show your thinking using drawings, numbers, or words.

Problem 2

Andre started a game with 32 seeds. Then he won more seeds. Now he has 57 seeds. How many seeds did Andre win?

  1. Label the diagram to represent the story.

    Diagram. One rectangle partitioned into 2 parts. 1 part, labeled, seeds at start. Total length, blank. Other part, labeled, seeds won. Total length, blank. Total length of rectangle, blank.

  2. Write an equation using a question mark for the unknown value.

  3. Solve. Show your thinking using drawings, numbers, or words.

Problem 3

Diego gathered 22 seeds from yellow flowers and 48 seeds from blue flowers. How many seeds did he gather in all?

  1. Label the diagram to represent the story.

    Diagram. Rectangle partitioned into 2 parts. All labels and total lengths blank.

  2. Write an equation using a question mark for the unknown value.

  3. Solve. Show your thinking using drawings, numbers, or words.

Problem 4

Noah and Kiran gathered 92 pumpkin seeds. Noah gathered 53 pumpkin seeds. How many seeds did Kiran gather?

  1. Draw a diagram to represent the story.

  2. Write an equation using a question mark for the unknown value.

  3. Solve. Show your thinking using drawings, numbers, or words.

Practice Problem

Problem 1

Lin read 25 pages of a book. Clare was reading the same book. Lin read 19 fewer pages of the book than Clare.

  1. Draw a diagram representing the situation.

  2. Write an equation using a question mark for the unknown value.

  3. How many pages did Clare read? Explain or show your reasoning.