What do you mean by how many problems appear in solving math problems in the third grade of primary school?
That is, how much is the unit to ask later? For example, a rectangle is 6 meters long and 2 meters wide. How many square meters is its area? How many square decimetres? That is, the area is calculated in square meters, and then the result is converted into the meaning that how many square decimeters are equal to how many square decimeters.