Students will be able to write expressions with variables to be able to identify the missing information in problems.

I can write expressions with unknown numbers using variables.

1.) [b]Variable:[/b] a letter that stands for an unknown number [br]2.) [b] Expression:[/b] a group of symbols, variables, and numbers used to represent a value or an amount[br]3.) [b]Equation:[/b] a group of symbols, variables, numbers and has an equal sign[br]4.) [b]Substitution:[/b] the process of replacing a variable with a number

When we have unknown information we need to fill the spot with something. When it comes to math we fill the unknown information with a [b]variable[/b]. [br][br][br]1.) Sarah and Miranda combine their students for an activity.[br] a.) Write an expression to represent how many students are doing the activity.[br][br][b]Step One: Identify all information that is provided and identify variables.[br][/b] There are two classes being combined.[br] We don't know how many students are in Sarah's class so let us represent the number with S.[br] We don't know how many students are in Miranda's class so let us represent the number with M.[br] We don't know the total amount of students participating so let us represent the number with T.[br][br][b]Step Two: Identify the operation that is being used.[br][/b] When we think of combining two groups to find the total amount participating we use addition.[br][br][b]Step Three: Write an expression using variables when needed.[br][/b] S + M = T[br][br] b.) If Sarah had 12 students and Miranda had 6 students, how many students are doing the activity?[br][b]We now have numbers to plug in to our equation so we substitute the known information into the equation[br][/b] 12 + 6 = T[br] 18 = T[br] There are 18 students that are doing the activity.