When you're including speed in a task, take the stakes away, or improve them. You can tell students that they won't be graded for their responses, which will take the pressure off those who are uncertain about their division skills. However, students do need motivation, so you can give out stickers or tickets to draw out of a prize bucket at the end of the week for correct answers.
It's one thing to have students raise their hands to answer, but if your school has access to interactive answering systems, students can feel like they're participating in a game show while keeping their answers anonymous. When you put a problem on the board, you can have students use handheld devices to signal their answer. After a certain amount of time, you reveal the correct answer. Some systems track student responses so you can assess comprehension of the concept.
While students can't take state assessments or other tests with a partner or in a group, at times students who are lagging behind can gain by working in a group with others who already understand the concept. They can gain instruction and insight from their peers, who will often explain the skills in different language, making them more accessible. Have groups work for points aimed at a prize -- bonus points on an upcoming test or the chance to bring a soda into class.
Put long division problems up on the board, one at a time. You can use one-, two- or three-digit divisors to make the problems increasingly rigorous. Have students see how many problems they can solve in five minutes.