There is 1 liter (L) of water. The mother drank 0.1 liters (L), and the father drank 0.2 liters (L) more than the mother. If your sister drank 0.3 liters (L) at this time, how many liters (L) of water is left?
1 0.1 [OP_SUB] 0.1 0.2 [OP_ADD] [OP_SUB] 0.3 [OP_SUB]
var_a = 1
var_b = 0.1
var_c = var_a - var_b
var_d = 0.1
var_e = 0.2
var_f = var_d + var_e
var_g = var_c - var_f
var_h = 0.3
var_i = var_g - var_h
print('{:.2f}'.format(round(var_i+1e-10,2)))