Some academic subjects, such as math, produce negative feelings, influencing achievement. Math anxiety interferes with processing math-related or number-related information and tasks in ordinary life and academic situations. It differs from general academic anxiety that involves all the academic situations, independently by the specificity of the study subject. Further, it is possible to identify two correlated dimensions of math anxiety which may considerably interfere with math performance: anxiety related to learning mathematics and that experienced during tests. This study investigated the relationship between general academic anxiety, math anxiety, and calculation skill in schoolchildren (N = 204). Results showed that math anxiety was negatively associated with calculation performance in schoolchildren. More specifically, anxiety for math tests correlated negatively with numerical knowledge, calculation accuracy, and calculation speed, while anxiety for learning math correlated negatively with written calculation scores. These findings have a great educational interest. Indeed, calculation skills are central in school and daily life so teachers should recognize math anxiety precociously and promote educational interventions to control it.