Need some insight on following python 3 code - python-3.x

Question

I was trying to build this basic code for fun but I ran into some weird error. The following code asks for an answer of a basic printed out equation. When the answer is 10 or greater, it is behaving weirdly. I tried to implement some error handling methods (the failure is at int(ansr_raw) I guess). I think a better method will help me out. You don't need to spell out the code for me but pointing me at the right direction will be helpful. The code and output are given below.
code -
import random
signs = ['+', '-']
verbals = ['out', 'quit', 'help', 'break']
while True:
a, b = random.randint(1, 9), random.randint(1, 9)
ch = random.choice(signs)
print("{} {} {} = ?".format(a, ch, b))
ansr_raw = input("Enter the answer: ")
if ansr_raw in '0123456789': # trying to handle error
ansr = int(ansr_raw)
else:
for i in verbals:
if ansr_raw == i:
choice = input("Wish to Quit? [y/n] ").lower()
if choice in 'yes':
print("Quit Successful.")
break
elif choice in 'no':
continue
else:
print("Wrong choice. continuing game.")
continue
print('answer format invalid')
continue
if ch == '+':
if ansr == (a + b):
print("Right Answer.")
else:
print("wrong answer.")
elif ch == '-':
if ansr in ((a - b), (b - a)):
print("Right Answer.")
else:
print("wrong answer.")
Here is the output (arrow marks added)-
9 + 3 = ?
Enter the answer: 12
answer format invalid <----
2 - 9 = ?
Enter the answer: 5
wrong answer.
1 - 3 = ?
Enter the answer: 2
Right Answer.
8 + 3 = ?
Enter the answer: 11
answer format invalid <----
1 + 2 = ?
Enter the answer: 3
Right Answer.
6 + 2 = ?
Enter the answer:

Answer 1

The problem is where you say
if ansr_raw in '0123456789': # trying to handle error
ansr = int(ansr_raw)
For a single digit number like 9, yes there is a 9 in that string, but there is only a few two digits(01,23,34,45,56,67,78,89), to what you're trying to do, check if the string can become an integer; do this.
try:
ansr = int(ansr_raw)
except ValueError:
Full Code:
import random
import sys
signs = ['+', '-']
verbals = ['out', 'quit', 'help', 'break']
running = True
while running:
a, b = random.randint(1, 9), random.randint(1, 9)
ch = random.choice(signs)
print("{} {} {} = ?".format(a, ch, b))
ansr_raw = input("Enter the answer: ")
try:
ansr = int(ansr_raw)
except ValueError:
answerInv = True
for i in verbals:
if ansr_raw == i:
choice = input("Wish to Quit? [y/n] ").lower()
if choice in 'yes':
print("Quit Successful.")
sys.exit(0)
elif choice in 'no':
continue
answerInv = False
else:
print("Wrong choice. continuing game.")
answerInv = False
continue
if answerInv:
print('answer format invalid')
if ch == '+':
if ansr == (a + b):
print("Right Answer.")
else:
print("wrong answer.")
elif ch == '-':
if ansr in ((a - b), (b - a)):
print("Right Answer.")
else:
print("wrong answer.")