Evaluating Algebraic Expressions
This Grade 6 algebra skill from Yoshiwara Elementary Algebra teaches students to evaluate algebraic expressions by substituting values for variables and simplifying. Students practice replacing variables with given numbers and applying the order of operations to compute the value of expressions with one or more variables.
Key Concepts
Property When we evaluate an algebraic expression, we substitute the given value for the variable and then we must follow the order of operations to simplify the resulting numerical expression. Parentheses indicate that we should perform the operations inside them first.
Examples To evaluate $5(x 3)$ for $x = 9$, we substitute 9 for $x$ and simplify inside the parentheses first: $5(9 3) = 5(6) = 30$.
A gym membership costs $25 + 10m$ dollars for $m$ months. For 6 months, the cost is $25 + 10(6) = 25 + 60 = 85$ dollars.
Common Questions
How do you evaluate an algebraic expression?
Replace each variable with the given number, then simplify using the order of operations (PEMDAS) to find the numerical value.
What is the order of operations for evaluating expressions?
Follow PEMDAS: evaluate inside Parentheses first, then Exponents, then Multiplication and Division left to right, then Addition and Subtraction left to right.
How do you evaluate 4a - 2b when a = 3 and b = 1?
Substitute: 4(3) - 2(1) = 12 - 2 = 10.
What is the difference between an expression and an equation?
An expression is a combination of numbers, variables, and operations without an equals sign. An equation has an equals sign and can be solved.
Where is evaluating algebraic expressions taught in Grade 6?
This skill is covered in the Yoshiwara Elementary Algebra textbook for Grade 6.