Solve Decimal Subtraction: Calculate 5.7 - 2.3

Let's solve the problem step by step:

• Step 1: Align the numbers by their decimal points:
  $\begin{array}{c} 5.7 \\ - 2.3 \\ \hline \end{array}$
• Step 2: Subtract the digits in the tenths place $7 - 3 = 4$.
• Step 3: Subtract the digits in the units place $5 - 2 = 3$.
• Step 4: Write down the result by combining both differences, making sure to keep the decimal point aligned: $3.4$.

Therefore, the solution to the problem is $3.4$.