Diabetic self-care requires the ability to use and comprehend numbers in order to perform daily self-care tasks that include calculating and understanding insulin doses, carbohydrate intake and glucose levels. These so-called quantitative literacy or numeracy skills seem to be lacking in many Spanish-speaking U.S. residents , an ethnic group at high-risk for type 2 diabetes. A study investigated how numeracy deficits among Latinos impact diabetes outcomes. Numeracy skills were measured using a revised Diabetes Numeracy Test consisting of 15 items in Spanish . Data on clinical status, socio-demographics, health literacy, general and disease-specific numeracy, acculturation and self-care skills and behaviors were collected. The study and all measures were mainly conducted in Spanish to adjust for poor English proficiency. The majority of the 144 subjects were Mexicans , female , without health insurance and with low acculturation levels . The DNT-15 Latino was highly reliable and correlated well with health literacy, general numeracy, educational level, acculturation and income but not to other variables. The DNT-15 Latino was shown to be a valid and reliable disease- and ethnicity-specific tool to measure numeracy skills in this patient population. There is a need for more studies and culturally tailored diabetes education programs : 893).