1 2======================== 3Expression: 1 4Object is a number : 1 5 6======================== 7Expression: 1+2 8Object is a number : 3 9 10======================== 11Expression: 2*3 12Object is a number : 6 13 14======================== 15Expression: 1+2*3+4 16Object is a number : 11 17 18======================== 19Expression: (1+2)*(3+4) 20Object is a number : 21 21