To convert 3 liters (L) to milliliters (mL), you can use the following steps. Note that the L will cancel out as you perform the conversion, leaving only mL:

Conversion Factor:

1 liter (L) = 1000 milliliters (mL)

Start with the quantity you want to convert (3 L) and set up a ratio where the original unit (L) is in the denominator and the target unit (mL) is in the numerator, using the conversion factor:

Conversion factor: 1000 mL / 1 L

Write the quantity you want to convert (3 L) as a fraction over 1: 3 L / 1

Multiply this fraction by the conversion factor: (3 L / 1) * (1000 mL / 1 L)

Notice that the units of liters (L) in the numerator and denominator cancel out, leaving only the units of milliliters (mL):

(3 * 1000) / (1 * 1) mL = 3000 / 1 mL = 3000 mL

So, 3 L is equivalent to 3000 milliliters. The units of liters cancel out during the conversion process, leaving only milliliters as the final unit.