A good way to check that code is working as intended, is to test it against a known outcome.

Prime numbers, for the most part, are well established and as such you can check your code against a list:

```
def prime_checker(number):
if number == 1:
return False
if number % 2 == 0 or number % 3 == 0:
return False
else:
return True
prime_list = [
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53,
59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113,
127, 131, 137, 139, 149, 151, 157, 163, 167, 173
]
for n in range(174):
check = prime_checker(n)
if check and n in prime_list:
print(n, "checks out")
elif check and n not in prime_list:
print(n, "does not check out")
elif not check and n in prime_list:
print(n, "does not check out")
```

I’ve include the first 40 prime numbers and modified your function so that it returns `True`

or `False`

.

This is the output for zero to 25:

```
2 does not check out
3 does not check out
5 checks out
7 checks out
11 checks out
13 checks out
17 checks out
19 checks out
23 checks out
25 does not check out
...
```

As you can see, you’ve not nailed this, but you’re trying, so that’s no bad thing.