Match each word to the correct definition. Warm-Up Match each word to the correct definition. Each part of an expression separated by an operation. B. A number that stands by itself C. A number that does not stand by itself (it is attached to a variable) A letter that stands for a particular numerical value E. A number sentence without an equal sign, has at least two terms and one operation Algebraic Expression 2. Coefficient 3. Constant 4. Term 5. Variable

1-1 Variables and Expressions You would be wise to listen carefully and take notes! Goal: to write algebraic expressions Algebra 1 Honors Ms. Register

mathematical quantity - anything that can be measured or counted. numerical expression – expression that represents a particular number Example: 3 + 2 algebraic expression - consists of one or more constants and variables along with one or more arithmetic operations. Example of an algebraic expression: 3x + 2 constants - numbers variables - letters operations - addition, subtraction, multiplication and division

Multiplication – use a dot or parentheses Here are some ways to represent the product of x and y. Use good form in an answer! factors - the quantities being multiplied Product – the result

Writing Algebraic Expressions In English there is a difference between a phrase and a sentence. In math, Phrases  expressions. Sentences equations or inequalities. Phrase The sum of 6 and a number 6 + n Sentence The difference of a number and three is five. n – 3 = 5 Sentence Seven times a number is less than 50. 7n < 50 When choosing a variable for an unknown, it may be helpful to select a letter that relates to the unknown value (for example: let a represent age). If a variable is given use it! Sentences must have a verb! Sentences must have a verb!

Would you say 5 notebooks or notebooks 5? The product of five and a number 5n The product of a number and five Would you say 5 notebooks or notebooks 5? 5n Write your answer in good form - the number comes before a variable in a term involving multiplication.

Use a fraction bar to designate division! Write an algebraic expression for each word phrase. a. The difference of a number and 7 n – 7 b. 32 increased by a number 32 + n c. 25 less than a number 25 n – d. 10 less the product of 5 and a number 10 – 5n e. The quotient of a number and six. n 6 Use a fraction bar to designate division!

Did you use a fraction bar to designate division? Example 1 Write the phrase as an algebraic expression. a. 11 greater than a number Did you use a fraction bar to designate division? n + 11 b. a number subtracted from 15 15 – n c. The sum of a number and 30 n + 30 d. Maria’s age minus 27 a – 27 18 n e. The quotient of 18 and a number f. The sum of a number and ten, divided by two.

Which of the following expressions represents 7 times a number decreased by 13? Answer Now

Which one of the following expressions represents 28 less than three times a number? Answer Now

Write a verbal expression for: 1) 8 + a. The sum of 8 and a 2) The ratio of m to r Do you have a different way of writing these?

Which of the following verbal expressions represents 2x + 9? twice a number increased by 9 a number increased by nine twice a number decreased by 9 9 less than twice a number Answer Now

Which of the following expressions represents the sum of 16 and five times a number? Answer Now