Whole Number Bias of Students in Fraction Number Line Tasks

This study used fraction number line estimation tasks to evaluate students' developmental patterns, and the relationship of such tasks with whole number bias was explored. In total, 189 fourth-grade students in a northern Taiwan elementary school were followed over 2 years. The results demonstrated that the students' fraction learning development pattern progressed from being nonlinear to linear, and none of the students' estimations exhibited a logarithmic pattern, as was the case in positive-integer number line estimation tasks. Many of the fourth-grade students (41.3%) did not exhibit a linear pattern of estimation and had clear whole number bias. By the fifth grade, half of these students still had a nonlinear pattern and could not treat fractions as integrated numbers. Instead, they were affected by whole number bias and mistakenly used the denominator to judge the actual fraction value.