Algebraic Expressions Notes 7th Grade

Algebraic Expression ordinary numbers variables (like x or y) An Algebraic Expression is a mathematical phrase that can contain: ordinary numbers variables (like x or y) operators (addition, subtraction multiplication and division)

Variables, operators and expressions A variable is a letter that stands for a missing number. An operator is add, subtract, multiply or divide. An expression puts variables together with operators.

a + 1 a - b 3 x x - a / b Examples: A number plus one The difference between “a” and “b” The product of three and a number A number “a” divided by a number “b” less than a number “x”

Key Words Addition increased by more than combined total of sum added to

Key Words Subtraction less than fewer than reduced by decreased by difference

Key Words Multiplication of w ( t ) times ( w ) ( t ) multiplied by

Key words Division per a out of ratio of quotient of ÷

Phrase to Expression nine increased by a number x 9 + x fourteen decreased by a number p 14 - p seven less than a number t t - 7 the product of 9 and a number n 9 · n or 9n thirty-two divided by a number y 32 ÷ y or

The use of “than” Whatever comes after the word “than” ALWAYS goes first! a number less than 5 5 - b a number more than 7 7 + n

Practice Fifteen less than twice a number Three times a number, increased by seventeen The product of nine and a number, decreased by six 30 + 7n 4/a - 5 Jenny earns $30 a day working part time at a supermarket. Write an algebraic expression to represent the amount of money she will earn in “d” days.

Answers 2a - 15 3a + 17 9a - 6 Seven times a number more than 30 Five less than four divided a number 30d

Vocabulary & Essential Question Complete the Frayer Model for each word. Variable Ratio Proportion Algebraic Expression Equation Essential Question: How is an algebraic equation like a balance?