A math task

My son asked me how to solve the math task when you know the volume of a cube and you need to find the area of all sides of the cube.

He thought he could solve it if he divides the volume of the cube by six. But I explained to him that he couldn't divide the volume by the sides, it was wrong.

This problem can solve by using cubic root but my son has said they haven't learned this topic yet. We started to try solving this task without using cubic root, but we couldn't find the right solution. Even Internet suggested the solutions with the root using only.

At last, we figured out the right answer. Because the children haven't know roots yet, they should use the method of matching just finding the right answer by trying the all numbers in order.