Translating Word Problems
Converting English phrases into math: 'sum' and 'more than' mean add, 'difference' and 'less than' mean subtract, 'of' and 'product' mean multiply, 'per' and 'quotient' mean divide, 'is' means equals.
Define the variable explicitly (let x = the number of nights) before writing the equation, and after solving, check that the answer makes sense in context — people, doses, and prices are rarely negative.