The Hearts and Flowers (H&F) task is a computerized executive functioning (EF) assessment that has been used to measure EF from early childhood to adulthood. It provides data on accuracy and reaction time (RT) across three different task blocks (hearts, flowers, and mixed). However, there is a lack of consensus in the field on how to score the task that makes it difficult to interpret findings across studies. The current study, which includes a demographically diverse population of kindergarteners from Boston Public Schools (N = 946), compares the predictive and concurrent validity of 30 ways of scoring H&F, each with a different combination of accuracy, RT, and task block(s). Our exploratory results provide evidence supporting the use of a "two-vector average" score based on Zelazo et al.'s approach of adding accuracy and RT scores together only after individuals pass a certain accuracy threshold. Findings have implications for scoring future tablet-based developmental assessments. [This is the online version of an article published in "Assessment."]