1. **State the problem:** Multiply 2.015 by 510.2. 2. **Formula used:** Multiplication of two decimal numbers. 3. **Step-by-step calculation:** - Multiply as if they were whole numbers: $2015 \times 5102$ - Calculate $2015 \times 5102 = 10284330$ - Count total decimal places: 2.015 has 3 decimal places, 510.2 has 1 decimal place, total 4 decimal places. - Place the decimal point 4 places from the right in 10284330. 4. **Final answer:** $$2.015 \times 510.2 = 1028.4330$$ or simply $$1028.433$$