Since all notcrows are not notblack, that would suggest that not all crows are black.
Here's a handy way to figure out the binary number of any base 10 number less than 512 (2^9) using your fingers. Pick the number, close your fingers, then count up your fingers from the left side of the left hand to the right side of the right hand.
For an example I've randomly picked 312.
On each finger, multiply by two, starting with 1. When you reach the FIRST number than is larger than your selected number, move one finger to the left and raise it. For 312, the first number that was larger was the 10th finger, 512, so we raise the 9th finger. Take the number that the raised finger represents (256), and subtract it from your number (312 - 256 = 56). Starting all over again from finger 1, repeat the process, counting up from finger 1 until you reach the FIRST number greated than the result (56). The first larger number would be 64 (7th finger, so raise the 6th finger). Now subtract 32 from 56 (56 - 32 = 24).
Keep repeating this process until you're done.
Now, starting from the first rightmost finger that is raised, write down a '1' for each raised finger, and a '0' for each lowered finger. Write down the binary from left to right.
There's your number!
For our example, 312, the number is: 100111000