算命 is a separable verb (离合词) meaning "to tell someone's fortune" or "to practice fortune-telling." It's formed from 算 (to calculate) and 命 (fate/life). As a v-o compound, you can insert measure words, objects, or time expressions between the two characters: 算一次命 (have a fortune-telling session), 算过命 (have had a fortune told). The person whose fortune is being told is typically introduced with 给 (gěi): 给我算命 (tell my fortune). Fortune-telling in Chinese culture covers various methods — face reading, palmistry, Eight Characters — and is still common in temples and street stalls.