Distinguishing Between Expressions and Equations
Distinguishing between expressions and equations is a fundamental Grade 6 algebra skill in Big Ideas Math Advanced 1, Chapter 7: Equations and Inequalities. An expression is a mathematical phrase with numbers, variables, and operations but no equals sign, while an equation is a mathematical statement asserting that two expressions are equal, connected by an equals sign.
Key Concepts
An expression is a mathematical phrase that contains numbers, variables, and operations but has no equal sign: $3x + 5$ or $2y 7$.
An equation is a mathematical sentence that shows two expressions are equal using an equal sign: $3x + 5 = 14$ or $2y 7 = 11$.
Common Questions
What is the difference between an expression and an equation?
An expression is a combination of numbers, variables, and operations without an equals sign (like 3x + 5). An equation has an equals sign that states two expressions are equal (like 3x + 5 = 20). Equations can be solved; expressions can be simplified or evaluated.
Can you give examples of expressions and equations?
Expressions: 4y, 2x + 3, 7 - n. Equations: 4y = 20, 2x + 3 = 11, 7 - n = 4. The key difference is the presence (equation) or absence (expression) of an equals sign.
Can you solve an expression?
No — expressions are not solved, they are evaluated (by substituting a value for the variable) or simplified. Only equations are solved, because solving means finding the value that makes both sides equal.
Where is this skill taught in Big Ideas Math Advanced 1?
Distinguishing between expressions and equations is covered in Chapter 7: Equations and Inequalities of Big Ideas Math Advanced 1, the Grade 6 math textbook.