Is 4 kilograms is egual to 4000mgs

No.

So, there are 1000 milligrams in one gram, making the 4000 mgs equal to 4 grams.

There are 1000 grams in one kilogram, so 4 kilograms is equal to 4000 grams.

4000 = / = 4

So, 4 kilograms and 4000 milligrams are not equal.

4000Mgs is not equal to 4 kilograms. 4000 Mgs is 4 grams, which is 0.004Kilograms. Hence, 1 milogram is 1x10^-6 Kilograms.