Children show understanding of fraction-related ideas years before learning about fractions in school (Begolli et al., 2020). We measured developmental changes in this understanding by tracking children’s production of fraction words across first and second grade. We investigated two questions: (1) Does frequency and accuracy of children’s fraction word use change over time? (2) How do children’s errors with these words change over time? As part of a larger study, 77 children completed the Informal Fraction Knowledge Assessment (Viegut et al., 2023) three times: start of first grade, end of first grade, and end of second grade. We analyzed the first 7 items, in which children helped characters share fairly (e.g., two bunnies share 6 carrot sticks) and explained their answer choice. We coded children’s explanations for the presence or absence of fraction words (e.g., “half”, “quarter”), the correctness of that usage, and the type of error if incorrect. Results highlight that children’s use of fraction words increases across 1st and 2nd grades (50% to 84%), even without formal fraction instruction, but errors with fraction words also increase. These findings raise new questions about how children’s growing informal knowledge can be leveraged to support formal fraction learning.
