Ganor-Stern Dana
Achva Academic College, Arugot, Israel.
Front Psychol. 2018 Jul 27;9:1316. doi: 10.3389/fpsyg.2018.01316. eCollection 2018.
Groups of children in 4th, 5th, and 6th grades and college students performed exact calculation and computation estimation tasks with two-digit multiplication problems. In the former they calculated the exact answer for each problem, and in the latter they estimated whether the result of each problem was larger or smaller than a given reference number. The analyses of speed and accuracy both showed different developmental patterns of the two tasks. While the accuracy of exact calculation increased with age in childhood, the accuracy of the estimation task reached its maximum level already in 4th grade and did not change with age. The reaction time of the exact calculation task was longer than that of the estimation task. The reaction time for both tasks remained constant in childhood and decreased in adulthood, with the improvement in speed larger for the exact calculation task. Similarly, within group variability in accuracy was larger in the exact calculation task than in the computation estimation task. Finally, low correlation was found between the accuracy of the two tasks. Together, these findings suggest that exact calculation and computation estimation reflect at least in part different skills.
四年级、五年级、六年级的儿童组以及大学生完成了两位数乘法问题的精确计算和计算估算任务。在精确计算任务中，他们计算每个问题的准确答案；在估算任务中，他们判断每个问题的结果比给定的参考数字大还是小。对速度和准确性的分析均显示，这两项任务呈现出不同的发展模式。虽然精确计算的准确性在儿童时期随年龄增长而提高，但估算任务的准确性在四年级时就已达到最高水平，且不随年龄变化。精确计算任务的反应时间比估算任务长。两项任务的反应时间在儿童时期保持不变，在成年期缩短，精确计算任务的速度提升幅度更大。同样，精确计算任务中准确性的组内变异性比计算估算任务更大。最后，发现两项任务的准确性之间相关性较低。总之，这些发现表明，精确计算和计算估算至少在一定程度上反映了不同的技能。
