Edia

Edia is an online worksheet generator that provides teachers with feedback on how their students are doing. The free version of the site has access to a huge database of questions for everything from middle school to high school math. Paid accounts have access to other resources and additional reporting tools. 

The site is most useful for reinforcing and testing what students learn in class. Questions on different topics can be assigned to the whole class (or individual students, on a paid account), either as assignments for them to practice or as quizzes that are marked (and you can decide how many times a student can submit an answer as well). One of the most impressive features of Edia is that it allows space for students to show their work vs. just inputting the answer. It also has a built-in math function generator so that students can clearly explain their work. This helps teachers see how a student not only answered but also arrived at their answer. On the student side of things, they get detailed explanations for any incorrect answers, including links to video explainers. 

One of the nicer elements of Edia is that it has flexible due date requirements. Teachers can assign a quiz or assignment to start and end on a certain date, and then provide some wiggle room for students, including late submissions. Edia also has anti-cheating/anti-equation reading elements built right into it, and the printable worksheets let teachers create a different set of questions for each student. The paid account unlocks this for online questions as well.