ALGEBRA

VARIABLES AND EXPRESSIONS Algebra – Uses symbols to represent quantities that are unknown or that vary. You can represent mathematical phrases and real-world relationships using symbols and operations. Quantity – Anything that can be measured or counted. Variable – a symbol usually a letter that represents a value.

VARIABLE AND EXPRESSION Numerical Expression – a mathematical phrase involving numbers and operations symbols, but no variables. Example: 1 + 4 = 5

VARIABLE AND EXPRESSION Algebraic expression – When variables are combined with symbols. Example x + 5 The expression x + 5 equals different values.

N + 5 X - 11 3m + - × ÷ Operation Word Phrases Expression 𝑎 7 or a ÷ 7 A number plus 5 Add 5 to a number Sum of a number and 5 5 more than a number A number increased by 5 N + 5 - A number minus 11 Subtract 11 from a number Difference of a number and 11 11 less than a number A number decreased by 11 X less a number 11 X - 11 × 3 times a number 3 multiplied by a number Product of 3 and a number 3m ÷ A number divided by 7 7 divided into a number Quotient of a number and 7 𝑎 7 or a ÷ 7

EXAMPLE 1 – WRITING EXPRESSIONS WITH ADDITION AND SUBTRACTION What is an algebraic expression for the word phrase? 32 more than a number n 58 less a number n

EXAMPLE 2 – WRITING EXPRESSIONS WITH MULTIPLICATION AND DIVISION What is an algebraic expression for the word phrase? 8 times a number n b) The quotient of a number n and 5

EXAMPLE 3 – WRITING EXPRESSIONS WITH TWO OPERATIONS What is an algebraic expression for the word phrase? 3 more than twice a number x 9 less than the quotient of 6 and a number x The product of 4 and the sum of a number x and 7

EXAMPLE 4 – USING WORDS FOR AN EXPRESSION What word phrase can you use to represent the algebraic expression 3x ? Expression 3x Word Phrase three times a number x or the product of 3 and a number x

EXAMPLE 5 – Writing a Rule to Describe a Pattern