Math Lesson ("Systems of Equations")
by Julie Poth: Elementary Science TSA
Pinellas County School District, Largo, FL
Students look at the total costs of rows and columns of whooping crane
food items and figure out how much each food item costs.
Students will explore logical reasoning using unknowns in studying
systems of equations. Students will use logical thinking instead of guessing,
checking, and revising.
out the Meal Deal handout
(1 per student). Also make a transparency of it to use on an overhead
projector. Each of the 9 squares on the handout contains a picture of
a meal worm, bowl of crane chow, or bunch of berries, all of which are
part of the Whooping Crane diet.
Note: The project costs are not actual costs. They
were adapted so the numbers were manageable for students.
the students that the total costs for each row or column is recorded
at the end of each column and row.
that each food item: meal worms, crane chow, and berries -- costs a
specific amount of money. Their goal is to look at the rows and columns
and figure out how much each of the food item costs.
- Ask the
students to look at the rows and columns and put an X on the one row
or one column they think would be the easiest to use to figure the cost
of one food item. Ask them to explain why they chose the ones they did.
will most likely identify row 3 with the three crane chows. Since the
total cost for three crane chows is $15, each crane chow must cost $5.
3 x ? = 15. If the students can’t explain this, guide them to
- The students
now have a piece of the puzzle to begin solving a system of equations:
They know that the crane chow cost $5. Ask, How can you use this
information to determine the cost of the meal worms or berries?
around the room to observe how the students are solving each element.
When they have determined the cost of the meal worms and the berries,
ask them to explain how they did so. After one student identifies how
he or she solved the problem, ask if anyone used another method.
Have the students design their own 3 x 3 Square Systems of Equations.
Meal Deal handout; teacher questions and observations