Writing Expressions Steps to writing a verbal expression

Writing Expressions

Steps to writing a verbal expression: 1. Write a model of the situation using words. 2. Define a variable. 3. Write an algebraic expression. What does it mean to define a variable? - You do this when you choose a variable to represent an unknown number.

Common Words/Phrases that indicate the operation in the expression Addition Subtraction Multiplication Division Plus Minus Times Divided Sum Less Product Quotient Total Less than Multiplied An, in or per Increased by Subtract Each Rate In all Decreased by Of Ratio More than Difference Factors Separate *LOOK FOR THESE WORDS TO HELP YOU DETERMINE THE OPERATION

Example 1 – Write an Algebraic Expression • Marcia is 5 years older than her brother. What don’t we know? Her brother’s age. We will use n to represent her brother’s age. Five Years older than 5 We represent this as 5 + n. + her brother’s age n

Example 2 – Write an Algebraic Expression • Anna makes nine dollars an hour. What don’t we know? How many hours she works. We will use n to represent the number of hours. Nine dollars 9 an hour ∙ n We represent this as 9 ∙ n or 9 n.

Example 3 – Write an Algebraic Expression • For the magic trick, the number I chose is ten less than the number the magician chose. What don’t we know? The number the magician chose. We will use n to represent the magician’s number. Ten 10 less than - We represent this as n – 10. magician’s number n LESS THAN IS A SWITCH PHRASE. This means you switch the order of the phrase

Now your turn! 1. The difference between seven and a number. 7 -n 2. The quotient of a number and nine. n ÷ 9 3. A four dollar tip is added to the bill. 4 + n 4. The product of twelve and a number. 12 n 5. We scored 5 points less than the other n-5 team.