Hands On Equations: Investigation 2: Working With Variable Expressions 
MMS Math
Essentials &
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Vocabulary 
Picture  Vocabuary 
Order of Operations PEMDAS: first> Parenthesis, Exponents, Divide, Multiply, Add, Subtract (last) Not following the order can lead to wrong solutions. 

Expression A mathematical phrase that combines numbers and/or variables using mathematical operations. An expression is a representation of a value; for example, variables and/or numerals that appear alone or in combination with operators are expressions. 5 + 6 – (3 + 2)/18 a + b – c 

Variable Variables are (usually) letters or other symbols that represent unknown numbers or values. a, b,c, n, x, y, z, speed, distance 

Equation A mathematical sentence that uses the equal sign (=) to show that two expressions are equal. 10 + 2 = 12 4a  3b = 1 