I used Khan Academy for 2-3 months while I had a full-time job. I worked my way up from College Algebra to Calculus I before I took community college courses i

I used Khan Academy for 2-3 months while I had a full-time job. I worked my way up from College Algebra to Calculus I before I took community college courses in Calculus I and Calculus II. It definitely prepared me for the college courses.