I completed UCMAS 8 levels in 5th grade. I did not go for grand level as i thought to go for abacus. I have a lot experience in UCMAS. Yes it builds your thinking period, Strategy Development, Time Management and most important Mentally solving skills. I do not say that the one who does not do UCMAS does not aquire this skill. But the one who does has more accuracy and confidence . This are some pros mentioned above. This is really really great if you complete levels when you are kid say (2–5) grade. 1 grade student can to join it but he should know 1 to 10 tables .This sounds funny but I heard that time when mam told to some parents.