To convert liters to cubic centimeters (cm³), we can use the conversion factor:
1 liter (L) = 1,000 cubic centimeters (cm³).
Now, to convert 3 liters to cm³:
\[ 3 \, \text{L} = 3 \times 1,000 \, \text{cm}^3 = 3,000 \, \text{cm}^3 \]
Next, we need to convert the 248 ml to cm³. Since 1 ml = 1 cm³, we have:
\[ 248 \, \text{ml} = 248 \, \text{cm}^3 \]
Now, we can add the two volumes together:
\[ 3,000 \, \text{cm}^3 + 248 \, \text{cm}^3 = 3,248 \, \text{cm}^3 \]
Finally, to convert cubic centimeters to cubic meters (m³), we use the conversion factor:
1 m³ = 1,000,000 cm³.
Now, we perform the conversion:
\[ 3,248 \, \text{cm}^3 = \frac{3,248}{1,000,000} \, \text{m}^3 = 0.003248 \, \text{m}^3 \]
Now, since "sm³" typically means "stere meters" (a cubic meter of volume), the answer in cubic meters is:
\[ 3 \, \text{L} + 248 \, \text{ml} = 0.003248 \, \text{m}^3 \]
Therefore, 3 liters and 248 ml is equal to 0.003248 m³.