### Unit 1

Unit 1

Operational Fluency of Addition and Subtraction

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 Key Vocabulary to Know Add: to join two or more quantities to get one sum Addend: any number used to get a sum Data: collection of information Difference: difference between two numbers (subtraction) Equal: having the same amount or value Equality: state of being equal Equation: mathematical statement containing an equals sign to show that two expressions are equal Fluent: solving facts quickly and accurately without halting, stumbling or reversing oneself Fewer: less than Graph drawing or diagram used to record information Inverse Operation: opposite or reverse operations (e.g. addition and subtraction) Minuend: the quantity that you are subtracting from in a subtraction equation Minus: to subtract More: greater than Number Line: line marked with numbers used to show operations Number Sentence: mathematical sentence written in numerals and mathematical symbols Plus: to add Related Fact: addition and/or subtraction sentences that are alike Scale: the increment used on a graph Strategy: a plan, a method or a way to solve a problem Subtract: to take one quantity away from another Subtrahend: the quantity subtracted from the minuend in a subtraction equation Sum: the total or whole amount; the result of adding