A free original bilingual lesson on mathematical operations defined by new symbols. Read the legend, replace each original operator once, preserve numbers and brackets, and then use ordinary arithmetic precedence. Separate simultaneous sign swaps from repeated replacement, and distinguish renamed signs from formula-defined two-input operations with ordered inputs and explicit grouping. Four worked cases, two unscored completion pauses, an analogy, a quick reference and four fully explained practice questions support accurate interpretation. Earlier arithmetic and BODMAS skills are recalled as needed. The lesson covers selected operator problems, not a new universal arithmetic rule or the full reasoning syllabus.