1. Method for verifying a credit card number:
Example:

2. Method for verifying a credit card number:
1. Starting with the second digit from the right,
Example:

3. Method for verifying a credit card number:
1. Starting with the second digit from the right, double every other digit
Example:
2 6

4. Method for verifying a credit card number:
1. Starting with the second digit from the right, double every other digit
Example:

5. Method for verifying a credit card number:
1. Starting with the second digit from the right, double every other digit
Example:

6. Method for verifying a credit card number:
1. Starting with the second digit from the right, double every other digit
Example:

7. Method for verifying a credit card number:
1. Starting with the second digit from the right, double every other digit
2. Break into digits,
Example:
= 70

8. Method for verifying a credit card number:
1. Starting with the second digit from the right, double every other digit
2. Break into digits, and add the digits together
Example:
= 70

9. Method for verifying a credit card number:
1. Starting with the second digit from the right, double every other digit
2. Add all digits together
3. Result must end with 0 (e.g 70)
Example:
= 70