i am new to this site so i apologize in advance...

i've been studying for the GMAT for about a month now and i took my first full practice test last week. i took my second one today and the scores are just not making sense to me. particular the quant section. the 1st test i took was

Kaplan and today i took GMAT Prep. I know

Kaplan tends to underestimate scores but the quant just didn't really make sense:

Test 1:

KaplanOverall - 640

Q: 44 - 32 out of 37 correct

V: 36 - 27 out of 41 correct

Test 2: GMAT Prep

Overall - 710

Q: 47 - 22 out of 37 correct

V: 41 - 29 out of 41 correct

How did my quant score go from a 44 to 47 when i got 10 more questions wrong?? Has anyone else seen this before? I am not sure what to think - I find it kinda hard to believe I got a 710 when I got so many questions wrong.