25128

Method 1 works because if circle keeps going up to 4 and triangle and square keeps going down they will get the answer sooner or later.

Method 2 works because 2 triangles +2 squares = 28, then a triangles + a square = 14. 3 squares + 1 triangle = 30, and 14 + 2 squares =30

Method 4 works because circle + square +4 =20.All the others are right.

Method 5 works because if they keep sudtracting, they will evetuly get it

Method 6 works because the numbers that they added up to the number below or beside.Also they don't use different for the same shape.

Method 7 will work if they keep on working in this way.