Quizlet has 26 flashcard sets on the topic of factoring trinomials. These sets come with flashcards that can be printed or else used online with an audio component. The flashcard sets also include a worksheet to study for the flashcards; it also has audio and can be printed out with answer sheets in addition to online use. The quizzes can be set for multiple choice, matching, true-or-false or written answers, and they can be printed out with answer sheets or played online.
Quia hosts a simulated game show with its Rags to Riches game online. Players are given questions with multiple-choice answers, and they win virtual money when they answer problems correctly. Quia also has two other interactive trinomial factoring games: Concentration and a matching game. Each requires players to answer polynomial factoring questions to make pairs necessary to win.
CoolMath offers trinomial factoring tutorials with colorful graphics and problems, with illustrated explanations of the answers after the tutorials. This site also has an Algebra Cruncher problem generator, which produces an endless amount of trinomial factoring problems for students to solve. The problems come with hints and answers with explanations.
Discovery Education's MathWeb site allows students to type in a trinomial, and the site will first find its greatest common factor, which will then be divided out of the trinomial, leaving the other factor.
ILoveMath's website has a printable PDF trinomial factoring card game. Students print out the cards, then match the expressions to their correct factored forms.