A children's book was placed on one side of the two-arm scale, and two 0.3 kilograms (kg) dolls and 0.5 kilograms (kg) toy cars were placed on the other side. How many kilograms (kg) is one children's book?
0.5 0.3 2 [OP_MUL] [OP_ADD]
var_a = 0.5
var_b = 0.3
var_c = 2
var_d = var_b * var_c
var_e = var_a + var_d
print('{:.2f}'.format(round(var_e+1e-10,2)))