Want to multiply three or more fractions or mixed numbers? It's easy: Turn the mixed numbers into improper fractions. Cross cancel where you can. Multiply straight across. (simplify and reduce if you did not completely cross cancel). This free video math tutorial presents a complete walkthrough of the process. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).