Teacher presentation materials. Unit: 6.6 Expressions and Equations (Grade 6). 6.6 Expressions and Equations In this unit, students learn to understand and use the terms “variable,” “coefficient,” “solution,” “equivalent expressions,” “exponent,” “independent variable,” and “dependent variable.” They begin to write coefficients next to variables without a multiplication symbol, e.g., \(10x\) rather than \(10 \boldcdot x\) , and note that \(x\) is \(1 \boldcdot x\) . They learn other situations in which the multiplication symbol can be omitted, e.g., \(6 \boldcdot (3+2)\) can be written \(6 (3+2).\) They work with expressions that have positive whole-number exponents and