To solve the subtraction problem, we need to ensure that both quantities are in the same unit before performing the subtraction. Since 1 kiloliter (kL) is equal to 10 hectoliters (hL), we can convert 24 hL to kL. After conversion, we subtract the two quantities to find the result in kL.
Step 1: Convert Units
To perform the subtraction, we first need to convert 24 hectoliters (hL) to kiloliters (kL). Since \(1 \, \text{kL} = 10 \, \text{hL}\), we have:
\[
24 \, \text{hL} = \frac{24}{10} \, \text{kL} = 2.4 \, \text{kL}
\]
Step 2: Subtract the Quantities
Now that both quantities are in kiloliters, we can subtract them:
\[
66 \, \text{kL} - 2.4 \, \text{kL} = 63.6 \, \text{kL}
\]
Final Answer
The result of the subtraction is:
\[
\boxed{63.6 \, \text{kL}}
\]