You divide the number which should be multiplied by 0.4 and get 8. How much would it be if you made it right?
8 0.4 [OP_MUL] 0.4 [OP_MUL]
var_a = 8
var_b = 0.4
var_c = var_a * var_b
var_d = 0.4
var_e = var_c * var_d
print('{:.2f}'.format(round(var_e+1e-10,2)))