Mathematics is a central tool for understanding the universe, yet how numbers are cognitively and neurally represented remains unclear. This is especially true when focusing on higher-level concepts, such as symbolic integers, including zero, and fractions. Twenty participants were scanned using a high-resolution 7T fMRI while performing a task in which they judged whether the current number was larger or smaller than the previous one. Behaviorally, we found that participants were slower and less accurate when two numbers were closer in distance on the number line. Neurally, our findings suggest that brain areas involved in mathematical processing – such as the intraparietal sulcus, inferior temporal gyrus, and prefrontal cortex - presented a graded neural BOLD response as a function of numerical distance on the number line. However, both behavioral and neural representations clearly distinguish between fractions and integers.