Less correct answers but higher score on practice tests?

Hi Shiftyeyes67k, this answer can get pretty elaborate, but let me highlight the important aspects for the scoring algorithm

1) The subject matter of the question is very important. If it's a complicated question about cubic roots and you get it wrong, your score might drop 10 points. If it's 2+2 and you write 6, your score might drop 40 points because the exam assumes you don't know anything about basic math. (the point drops are for illustrative purposes only)
2) Long strings of right/wrong affect your score much more than oscillating between right and wrong. If you get question 1 right then 2 wrong then 3 right then 4 wrong etc, your score won't really move at all. You're somewhere between 500 and 520. If you get 10 right in a row, your score will go up a fair bit, if you then get a few wrong then a few right it won't move much afterwards. Long strings of correct answers boost your grade much more than two in a row right then one wrong.
3) Some questions are experimental, which means they don't actually count towards your score. On the real GMAT 7-8 questions per section fall into this category, so many practice tests mimic this scoring guide, so luck plays a bit of a factor in your grade (from 550 to 570, not from 550 to 750).
4) Some people postulate that the first 10 or last 10 are more impactful than the middle 20, but this is very hard to corroborate so take it with a grain of salt. I personally am not a big believer in this strategy of focusing on the first and last 10 and jogging through the middle, but it's a strategy like any other.

In conclusion, if your score is going up, it's very likely you're better covering your bases and missing less "easy" questions. This is a good sign for your prep and eventual exam.

Hope this helps!
-Ron