Calculate the Sum: Finding 1.54 + 0.27 Step-by-Step

To solve the addition problem of $1.54 + 0.27$, we start by aligning the numbers by their decimal points:

• Step 1: Write the numbers vertically, one under the other, ensuring that the decimal points are aligned:
  $\begin{array}{c} ~~~1.54 \\ +0.27 \\ \hline \end{array}$

• Step 2: Add the digits starting from the rightmost column (hundredths place):
  - Hundredths place: $4 + 7 = 11$. Write down $1$ and carry over $1$ to the tenths place.
  - Tenths place: $5 + 2 = 7$ plus the carried over $1$ gives us $8$. Write down $8$.
  - Ones place: $1 + 0 = 1$. Write down $1$.

• Step 3: Combine the results:
  $\begin{array}{c} ~~~1.54 \\ + 0.27 \\ \hline ~~~1.81 \\ \end{array}$

Therefore, the sum of $1.54$ and $0.27$ is $1.81$.

From the given answer choices, the correct answer is choice 1: $1.81$.