Design and evaluation of a systematic finger-based intervention for early numeracy in 5- to 6-year-olds.

Early numeracy is a building block for later mathematics achievement in school. Recently, the use of fingers in early numeracy instruction received increasing attention as a prominent example of embodied cognition. Accordingly, the present study developed and evaluated a finger-based intervention for early numeracy skills (involving 12 sessions of 30 min each) that (1) systematically aligns with early numeracy development on all three levels (counting, cardinality understanding, and basic arithmetic) proposed by a recent model of numerical development and (2) using fingers as primary and embodied manipulatives. In a pre-posttest intervention design, 33 5-to-6-year-old children received the finger-based numeracy intervention and were compared to children of a business-as-usual control group (n = 37). Results indicated a significant medium-sized beneficial effect on early numeracy, whereas no significant improvements were observed for spatial working memory or fluid reasoning. Interestingly, the number of finger users increased from pre- to posttest but did not differ between children who received or did not receive the finger-based intervention. Irrespective of group assignment, finger users consistently outperformed non-finger-users in early numeracy. Taken together, these findings highlight that finger use is a powerful and beneficial approach for fostering the development of early numeracy.