1. The problem is to multiply 13.6 by 2.1. 2. The multiplication formula is straightforward: $a \times b = c$ where $a=13.6$ and $b=2.1$. 3. Multiply the numbers: $13.6 \times 2.1$. 4. Calculate step-by-step: $13.6 \times 2 = 27.2$ and $13.6 \times 0.1 = 1.36$. 5. Add the partial products: $27.2 + 1.36 = 28.56$. 6. Therefore, the final answer is $28.56$.