To answer this question, you need to know the volume of each box of dumplings. Generally speaking, boxes of dumplings are of standard size, usually around 30x20x5 centimeters. Assuming that each box of dumplings measures 30x20x5 centimeters, then you can calculate the volume of each box of dumplings to be 30x20x5 = 3000 cubic centimeters.

To find out how many boxes of dumplings the insulated box can hold, you need to compare the volume of the insulated box with the volume of each box of dumplings. Assuming the volume of the insulated box is 30 liters, this can be converted to 30,000 cubic centimeters (1 liter = 1000 cubic centimeters).

Dividing the volume of the box by the volume of each box of gyoza gives the number of boxes of gyoza: 30,000 / 3000 = 10 boxes.

So, a 30-liter insulated box can hold up to 10 boxes of takeout dumplings. However, it is important to note that this is only an estimate and the actual situation may vary somewhat.