Balance—Solving for Unknowns, Part One

BALANCE—SOLVING FOR UNKNOWNS, PART ONE

Grades: 4‒7

This activity is the first of three balance activities in which students develop intuitive strategies for writing and solving simple algebraic equations. Students drag a shape whose numerical value is known onto one side of a scale. They then drag copies of a shape with an unknown numerical value to the other side of the scale until both sides are level. Students represent this relationship with a repeated addition equation, which they simplify to a multiplication equation. Students then solve the equation to determine the value of the unknown shape. These actions are repeated for each of the shapes whose value is unknown.

OBJECTIVES

Students will use a scale to represent algebraic equations.
Students will understand that repeated addition can be expressed as multiplication.
Students will develop and use intuitive strategies to write and solve algebraic equations in which there is one unknown value.
Students will develop and use intuitive strategies to solve for an unknown value in cases where that value is only on one side of an equation.

COMMON CORE CONNECTIONS

Mathematical Practices

(1) Make sense of problems and persevere in solving them; (2) Reason abstractly and quantitatively; (3) Construct viable arguments and critique the reasoning of others; (5) Use appropriate tools strategically; (7) Look for and make use of structure.

Content Standards

6.EE2, 4, 5, 6, 7; 7.EE4

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