My SAT score did not improve despite a significant change in the number of questions I got correct.

I took an SAT test and scored 1330 (this was Practice Test 1). A month later I took another SAT test and scored 1430 (Practice Test 10). 

The problem was that I got the exact same Reading and Writing score despite a significant change in the number of questions I got correct.

In reading, I got 4 more correct than my first test and in writing, I got 5 more correct yet despite this I still got a 660. Can someone please help me understand why my score did not improve? 

Thanks in advance.

PS Here are my numbers

Practice Test 1

Reading: 9 wrong   Writing: 11 wrong

Overall Score: 660

Practice Test 10

Reading: 5 wrong   Writing: 6 wrong

Overall Score 660