From what I've learned the raw scores differ from test to test. For example digitspan has a lower total points than similarities because there are fewer "problems" and they might give different amount of points if success. For example: you can only get digitspan right if you remember all digits presented however an answer to similarities can give 0-1-2 points depending on quality.

1 scaled point is 5 iq points and a scaled score of 10 is average - 100 IQ. So a score of 19 would be 145 IQ. The real interest is what percentil a score belongs to. For example (scaled score 10) 100 iq is in the 50%, (scaled score 13) is 115 is 84% and scaled score 19 is 145 99.9%

Chart of scores!