The question, as stated, cannot be answered sensibly. A gallon is a measure of volume, with dimensions [L3]. A milligram is a measure of mass, with dimensions [M]. The two measure different things and basic dimensional analysis teaches that you cannot convert between measures with different dimensions such as these without additional information.
As a simple mental exercise consider a gallon of air and of water. They will have very different masses.
There are 5,000 milliliters in 5 liters.
5125 ml are in 5 liters and 125 milliliters.
.5 liters is equal to 500 milliliters
there are 1000 milliliters in a liter, so .5 liters is 500 milliliters.
there are 5,000 milliliters in 5 litersthere are 1,000 milliliters in one liter
5,000 milliliters is 5 liters.
5 liters is 5,000 milliliters.
5000 ml
5 000 milliliters 5,000
50 milliliters = 0.05 liter50 milliliters * 1 liter/1000 milliliters= 5 liter/100= 0.05 liter
5500ml
5500