So I gave my 6th grade math class their first test of the year only to realize that at the end of the 50 min., they only got through about 3/4 of the way. So now what? Do I grade what they completed and give them time on Monday to finish the rest? Or do I just give them a grade for what they completed and call it a day? New teacher...you live and you learn!

Let them finish the test,although I would not give them back the part that you already graded,if they have done poorly they will give up on the remaining part of the exam.

Two options: 1) Give them extra time on Monday 2) Pro-rate it. Assuming that all the kids actually worked all period, divide the points they earned by the points they attempted, and make it into a percent. It's all part of learning to teach. Don't sweat it. And, for the record: I've found that this is a great way to determine what a typical class can do in a 40 minute period: I type the test, leaving room for them to show work. If it fits onto a standard 8.5x11" piece of paper, an average class can probably finish it in one period.

I would say give them time to complete it on the following class day. My mom was a math instructor and when she would check to see if all of her students completed their tests and found that they hadnt, she would give them a portion of the next class to complete it.