Improving early mathematical competence is a major priority worldwide; thus, assessing early math abilities is critical. Although various international standardized instruments serve this purpose, their usage in underdeveloped countries is prohibitive due to their resource-intensive requirements. In this report, we explore the development of the "Test de Pensamiento Matemático" (TPM, Test of Preschool Mathematics), which is an automated, game-based, digital instrument for assessing early math abilities in 4-to-6-year-old children in accordance with international curricular standards. A confirmatory factor analysis shows an optimal fit for two dimensions: numerical thinking and visuospatial reasoning. By drawing on technology, the TPM can be applied to large groups of children, so it becomes an efficient tool for assessing performance, monitoring learning improvements, and screening children who need additional support to develop their math abilities at the same pace with their peers.