Algebraic thinking and strategy flexibility are essential to advanced mathematical thinking. Early algebra instruction uses 'missing-operand' problems (e.g., x - 7 = 2) solvable via two typical strategies: (1) direct retrieval of arithmetic facts (e.g., 9 - 7 = 2) and (2) performance of the inverse operation (e.g., 2 + 7 = 9). The current study…

If numerical reasoning items are administered under time limits, will two dimensions be required to account for the responses, a numerical ability dimension and a speed dimension? A total of 182 college students answered 74 numerical reasoning items. Every item was taken with and without time limits by half the students. Three psychometric models…