Summary
This lesson focuses on using a symbol/shape variable to represent a missing value in a mathematical equation.
Materials
Additional Resources
Books
- M&M's Counting Book, by Barbara Barbieri McGrath;
ISBN 0-88106-853-5
- Hershey's Kisses Addition Book, by Jerry Pallotta;
ISBN 0-439-24179-1
- Hershey's Kisses Subtraction Book, by Jerry Pallotta;
ISBN 0-439-33779-8
- Counting Crocodiles, by Jody Sierra and Will Hillenbrand;
ISBN 0-15-200192-1
- Fish Eyes, by Lois Ehlert; ISBN 0-440-846-47-1
- One Less Fish, by Allan Sheather; ISBN 0-613-08482-9
- Mathematickles, by Betsy Franco; ISBN 0-689-84357-7
Student Prior Knowledge
Students need to be proficient
with the addition and subtraction of numbers 0-10.
Intended Learning Outcomes
2. Develop social skills and ethical responsibility.
5. Understand and use basic concepts and skills.
Instructional Procedures
Invitation to Learn
Read the story Fish Eyes (for addition) or One Less Fish (for
subtraction). As the story progresses, stop at each page and write the
equation represented using a variable for the answer. Have the students
come up with the missing value for the variable. Use a different shape
symbol for each page so students get the idea that a variable can be
represented many different ways.
Instructional Procedures
Whole Group Activity
- Show a variety of symbols/shapes to students and teach them
that the shape’s job is to hold the place of the missing value or
number. Make sure they have made the connection to how it
was used in place of the missing sum or difference in the story.
- Have the large Symbol Cards and Number Cards in separate paper bags. Select two students to pick
numbers from the number bag and one student to pick a
symbol. Also, select two students to be the addition or
subtraction sign and the equal sign.
- Have selected students put themselves in the correct order to
form an equation. Have another student give the sum or
difference of the equation. Repeat this process several times.
- After the activity, using the small Number Cards and Symbol
Cards, repeat the process by placing addends or minuends on the
board to the left of the = sign with a shape on the right of the =
sign, forming an equation.
- Students provide the missing sum or difference by writing it on
the shape, or use number tiles for students with writing
deficiencies. Repeat this process until the students understand the
meaning of the shape.
- Switch the placement of the addends or minuends to the right of
the = sign and the shape on the left, forming the reciprocal of the
equation, and allow students to provide the missing sum or
difference again. Repeat as needed for students to clearly
understand.
Small Group Activity
- Distribute Missing Number independent practice pages to
students.
- With a partner, students practice making mathematical sentences
with a group of numbers 0-9 and an assortment of shapes.
- Students write the sum or difference (depending on the
worksheet) on the shape.
Hint: Carefully select addends so sums will not be higher than 12
and minuends so differences will not be negative. Watch
carefully how students represent subtraction equations.
Extensions
- Place the shape in place of one of the addends or minuends in a
mathematical sentence to extend as a follow-up lesson.
- This lesson provides the background information needed for a
lesson on addend order (Standard 2, Objective 2,c).
Family Connections
Encourage the students to either play the game at home and/or
share with their parents what they have learned.
Assessment Plan
- Observe during the lesson which students are able to represent an
equation with the proper symbols and which students may need
teacher assistance during the partner-guided practice. Partner
those students who struggle with a student who understands, using
them as a peer tutor. Use the partner-guided practice as an informal assessment tool. Note which students may need extra
help.
Created: 09/15/2004
Updated: 02/05/2018
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