Coins QuandaryTeacher Notes

Coins QuandaryTeacher Notes

Vocabulary: system of equations• Prepare 1 box (or envelope) per student.• Supplies:• pennies & nickels• boxes or containers that can be closed and are not

see-through• Grouping: Individual

Coins QuandaryCoins Quandary

Systems of Equations

©Evergreen Public Schools 2010 3

©Evergreen Public Schools 2010 4

Systems of Equations Learning Targets Create equations with 2 variables to represent relationships

between two quantities with equations and tables. Solve a system of linear equations algebraically to find an

exact solution.

©Evergreen Public Schools 2010 5

What does a system of equations look

like?

Unit Launch• Do NOT open the box.• The box has pennies and nickels.You will know • the number of coins in the box.• the value of the coins in the box.Your task:• How many of each coin are in the box?Be prepared to explain your thinking.

Share Your Solution• Do NOT open the box.• Your will be paired up someone that had a

different problem than yours.• Person A will share their solution with Person B.• Person B will listen and verify Person A’s solution.• Person A will edit results if needed.Now reverse the process.

How Many Coins?• Do NOT open the box.• Write up your problem and solution.

How Many Coins?• Do NOT open the box.• Some students will present their solution to

the class.• As you listen you may make changes to your

work.

How Many Coins?• You can now open the box.• Where you right?

More MoneyWork with a partner on this problem.• Penny has nickels and dimes in her pocket. She has 53

coins worth $4.20. • How many of dimes does she have? • Write up your solution on the same paper.

More CoinsWork with a partner on this problem.• Sheldon has pennies, nickels and dimes in his pocket. He has 50

coins worth $2.73. • How many of each coin could he have? • Find more than one solution. • Write up your solution on the same paper.