Two-step problem solving

1. Determine the corresponding value of each graph.

Judging from 3, 1, 6 and 4, the square can be added and subtracted.

Basically, it can be concluded that

Square = 1

Circle =2

Triangle =5

2. Determine whether to add or subtract.

On the basis of the first step, observe 6 and 4. If you want to meet the first step, the triangle can be reduced outside and added inside.

So the last method should be subtraction.

Answer: 5-2=3