Write variable expressions: word problems

Learning Objectives Identify keywords in word problems that indicate mathematical operations. Define variables to represent unknown quantities in word problems. Translate verbal phrases involving addition and subtraction into algebraic expressions. Translate verbal phrases involving multiplication and division into algebraic expressions. Construct multi-step variable expressions from complex word problems. Correctly use parentheses to group terms in expressions when necessary. Ever wonder how mathematicians turn everyday language into powerful problem-solving tools? 🤔 It all starts with understanding how to translate words into mathematical expressions! In this lesson, you'll learn the essential skill of converting written descriptions of quantities and relationships...

TermDefinitionExample VariableA symbol, usually a letter (like x, y, n), used to represent an unknown quantity or a quantity that can change.In the phrase 'a number increased by 5', 'a number' would be represented by a variable, such as 'x'. Algebraic ExpressionA mathematical phrase that contains numbers, variables, and operation symbols (like +, -, ×, ÷), but does not contain an equality (=) or inequality (<, >) sign.The phrase 'three times a number minus seven' translates to the expression '3x - 7'. ConstantA value that does not change; it's a fixed number in an expression.In the expression '2y + 9', the number '9' is a constant. CoefficientThe numerical factor multiplied by a variable in an algebraic term....

Addition Keywords $$a + b$$ Use for phrases like 'sum of', 'increased by', 'more than', 'plus', 'total of', 'added to'. Subtraction Keywords $$a - b$$ Use for phrases like 'difference between', 'decreased by', 'less than', 'minus', 'subtracted from'. Be careful with 'less than' and 'subtracted from' as they reverse the order of terms. Multiplication Keywords $$a \cdot b$$ or $$ab$$ Use for phrases like 'product of', 'times', 'multiplied by', 'of' (especially with fractions or percentages), 'twice', 'double', 'triple'. Division Keywords $$a \div b$$ or $$\frac{a}{b}...