I would like to know more about the BS Math Major at Lafayette. Is there any chance to hear about the experience from an older student. Also, is the financial aid award offered almost the same throughout the 4 years of education, as long as my parents’ finances don’t change and I continue to provide satisfactory GPA, or is there a chance for my award to decrease. International here. Thanks in advance 
Your award should stay the same (you can fill an appeal form to ask for more aid provided that you have sufficient supporting document), but the amount of aid is unlikely to decline.
The math department is among the most active departments on campus; there are tons of activities each semester: math talks, calculus cavalry, barge competition, putnam competition (annually), problem solving group, … The professors are also super humorous and helpful.
There is an abundance of interesting 300-level courses, so if you want to make the most out of your education, take Math 263 (Calc 3) in the fall semester, then Math 290 (intro to theoretical math) in the spring, and starting from your sophomore year you are eligible to take any math course you like. Also, if you officially declare yourself as a math major, you have the freedom to pick your own math advisor.