Students will be able to identify, explore, and apply the standard algorithm for dividing decimals by a whole number in order to solve real-world math problems.
- Ask students to think about their experiences of dining at a restaurant.
- Ask students how math is used when they dine out.
- Make a list of student responses on the board (e.g., wait time, table number, menu prices, bill).
Explicit Instruction/Teacher modeling(15 minutes)
- Tell students that today they will be solving problems to find out how much each person owes if they split the check at a restaurant.
- Ask students what operation would work best for this task.
- Once students have decided division would be the most convenient, ask them what form the total on a restaurant bill would be in. Have them think of what this number would look like. Have them give examples of dollar amounts.
- Write one of these values on the board.
- Review vocabulary by labeling each part of the number: "decimal," "tenths," and "hundredths."
- Explain that since they will be working with money, the students will need to divide a decimal by a whole number and round their answers to the nearest hundredth.
- Watch the video "Dividing a Decimal by a Whole Number" (see related media).
- After the video, pose sample problems and model solving them using long division.
Guided Practice(10 minutes)
- Invite volunteers to practice additional sample problems on the board.
- Review the rules for the Diner Division Dash game.
- Model playing the game with a small group of students.
- Clarify directions and answer any student questions.
Independent working time(15 minutes)
- Have students work in groups to play Diner Division Dash.
- Circulate the room to guide student engagement and help resolve any problems that may arise.
- Preview vocabulary to build background knowledge for struggling students. Scaffold your instruction by first model dividing 3–4 digit numbers by a whole number.
- Given an amount of money to dine, students will identify which combinations of diner cards and restaurant receipt cards they could afford to dine with.
- Have students create their own unique restaurant dining scenario.
- In their math journals or on scratch paper, tell students to create a restaurant receipt with a total and to divide it by the number of diners.
- Remind students to check their division by using multiplication.
Review and closing(5 minutes)
- Discuss the game by asking the following questions: Which diner card and restaurant receipt combination would make for the most expensive meal? How about the least expensive? How would you choose to split the bill when you eat out with friends?
- Review division with decimals by having students turn and talk to their partners and answer the following question: What steps are important when dividing decimals by whole numbers?