Solve the Addition: Finding the Sum of 100 + 10.3

To solve this problem, we'll add the numbers 100 and 10.3.

Let's break down the steps as follows:

• Step 1: Align the numbers vertically by the decimal point. While $100$ is a whole number, it can be written as $100.0$ to facilitate alignment. Therefore, write the numbers as: $\begin{array}{r} 100.0 \\ + 10.3 \\ \hline \end{array}$
• Step 2: Proceed with addition, starting from the rightmost digits. The setup allows addition digit-by-digit:
• Add the tenths place: $0 + 3 = 3$.
• Add the ones place: $0 + 0 = 0$.
• Add the tens place: $0 + 1 = 1$.
• Add the hundreds place: since there's nothing above the 1, it remains $1$.
• Step 3: Carefully maintain the decimal position. The result of this addition will be $110.3$.

Therefore, the sum of $100 + 10.3$ is $110.3$.