S: (v) reason (think logically) "The children must learn to reason"
S: (v) think, cogitate, cerebrate (use or exercise the mind or one's power of reason in order to make inferences, decisions, or arrive at a solution or judgments) "I've been thinking all day and getting nowhere"
W: (n) subtraction [Related to: subtract] (an arithmetic operation in which the difference between two numbers is calculated) "the subtraction of three from four leaves one"; "four minus three equals one"
W: (n) subtraction [Related to: subtract] (the act of subtracting (removing a part from the whole)) "he complained about the subtraction of money from their paychecks"
W: (n) deduction [Related to: deduct] (the act of subtracting (removing a part from the whole)) "he complained about the subtraction of money from their paychecks"