The value of ADA can be determined by looking at the pattern established by the given examples. Each letter is assigned a numerical value based on its position in the alphabet. For example, A is 1, B is 2, C is 3, and so on. In the given examples, ADD is equal to 9, which means A = 1, D = 4, and D = 4. Similarly, BAD is equal to 7, which means B = 2, A = 1, and D = 4. CAD is equal to 8, which means C = 3, A = 1, and D = 4. Therefore, the value of ADA can be calculated as A = 1, D = 4, and A = 1, which adds up to 6.