Math PhD Applications: Is it better to show just my good GRE score, or should I also send my low initial score? I am applying for mathematics PhD programs in the United States. 

I did not major in mathematics as an undergrad and I did not do so well the first time around on the GRE Math subject test (about 60th percentile). I have since completed a Master's in mathematics and my score has improved to about 90th percentile.

I think it could benefit me to send both scores since it shows my progress. Will admissions committees in general view this in a positive light? Or should I just send my most recent good score.
Send your best one. GRE is typically used simply as a filter and including your lower score will probably hurt you more than it helps.