Materials & Prep
Prepare one choice organizer for each student with four boxes: Choice made, Other options, Next-best option given up, and Explanation. Display or write the four investigation scenarios in the collaborative work section. No special materials are needed beyond the board and student paper.
Opening choice
Ask“You have 15 minutes before dismissal. You may either play a basketball game with your friends or finish reading a book you chose. Which would you choose?” Students silently point to or write their choice, then turn and talk: “What would you not be doing because of your choice?” Accept answers such as “I would give up basketball” or “I would give up reading.” Do not introduce the term opportunity cost yet.
ConnectExplain that students just noticed an important idea about choices: choosing one option means giving up another option. Say, “Even if you pay no money, your choice still means you cannot use that time for the next-best thing.” Introduce the term opportunity cost as the next-best alternative given up when a choice is made. In the example, if a student chooses basketball and would most want to read, reading is the opportunity cost. The opportunity cost is not every option and is not automatically money.
Model opportunity cost
Display“After school, Lena has one hour. She can visit the library, practice soccer, or play a video game. She chooses to visit the library. She would have chosen soccer next.”
Think aloud“First, I name the choice Lena made: visiting the library. Next, I list the alternatives: soccer and a video game. I do not call both alternatives the opportunity cost. I identify the next-best alternative, which is soccer. Lena gives up the chance to practice soccer, so soccer practice is the opportunity cost. She paid no money, but she still gave up something valuable to her.”
ConfrontWrite the incorrect response, “The opportunity cost is $0 because Lena paid nothing.” Ask students to show thumbs up or down, then explain why it is incorrect. Clarify that $0 describes money paid, while opportunity cost describes the next-best alternative given up. If Lena had paid $4 for a bus ride to the library, the $4 would be a monetary cost, but soccer practice would still be the opportunity cost if it was her next-best alternative.
Check for understandingPresent this quick example: “A class uses its 30-minute free period to watch a science video instead of going outside or drawing. Most students would choose going outside next. What is the opportunity cost?” Students answer on fingers, mini whiteboards, or paper. Look for “going outside,” not “nothing” and not “drawing and going outside.”
Guided practice
Worked exampleComplete the first row of the organizer together: “The school has $200 for one improvement. Students choose new playground balls instead of new art supplies or plants for the courtyard. Students would choose art supplies next.” Model each box: Choice made: new playground balls. Other options: art supplies and courtyard plants. Next-best option given up: new art supplies. Explanation: “The opportunity cost of buying playground balls is the art supplies the school gives up.”
Turn and talkAsk, “Why is the opportunity cost not the courtyard plants?” Require students to use the sentence frame, “It is not because was the next-best alternative.” Invite one student to explain that opportunity cost is the single next-best alternative, not every option that was not chosen.
Have students complete one row with a partner: “During a 20-minute study period, Amir chooses to work on a history project. His next-best choice was reading a mystery book.” Partners identify the choice and opportunity cost, then compare their answer with another pair. Circulate and ask, “Was money paid? Does that decide the opportunity cost? What was the next-best choice?”
Choice trade-off investigation
Students work in pairs on the organizer. For each scenario, they identify the choice, list the alternatives, name the next-best alternative, and write an explanation using “The opportunity cost of is because it was the next-best alternative given up.”
Scenario 1: The class has 25 minutes for an activity. It chooses to create posters about recycling instead of reading a class novel or playing a math game. Most students would choose the math game next.
Scenario 2: Jordan has Saturday morning free. Jordan chooses to help a neighbor rake leaves instead of riding a bike or building with blocks. Jordan would choose riding a bike next. Jordan receives no money for helping.
Scenario 3: The town council can use an empty lot for a small park, a farmers’ market, or extra parking. The council chooses the small park. Residents say the farmers’ market was the next-best option.
Scenario 4: A family has one hour during a trip. It chooses to visit a history museum instead of swimming or watching a movie. The family would choose swimming next. The museum visit is free.
ScaffoldKeep the completed playground-balls row visible. Students who need support may first circle the chosen option, underline the next-best option, and use the sentence frame. They may explain orally to a partner before writing. Pair students so one reader reads each scenario and the other records, then switch roles.
DiscussAfter checking responses, ask, “In which scenario was no money paid? Did those choices still have opportunity costs? What evidence shows that?” Also ask, “Could two people make the same choice but have different opportunity costs?” Guide students to see that the opportunity cost depends on each person’s next-best alternative. For example, one student choosing the library may give up soccer, while another may give up drawing.
ExtensionStudents create their own school or community choice with three realistic options. They name the choice, identify the next-best alternative, and explain how the opportunity cost would change if a different person valued the alternatives differently.
Closing check
Exit ticket“The student council has 40 minutes after lunch. It chooses to rehearse a play instead of playing outside or finishing a group art project. The group would have chosen playing outside next, and no money is spent. Explain the opportunity cost. Then explain why ‘there was no cost’ is not a complete answer.”
ExpectedStudents identify playing outside as the opportunity cost and explain that opportunity cost is the next-best alternative given up, even when no money is paid. Collect the tickets. Students who name only “$0” or “nothing” should revise the response orally using the frame, “The money paid was , but the opportunity cost was because .”