Getting Students Motivated

Last week and this week I have been teaching Spelling and Reading. One of the things I have noticed is that students have a hard time getting motivated in the classroom. Many students tend to get lazy and not care to pay attention. A lot of students do poorly on tests and do not keep up with their homework assignments. Something that all three of the 5th grade teachers do is give out stamps when students are "caught being good". After they receive so many, then they are rewarded with the choice to have free time on the computer, eat lunch with a friend, etc. It works really well with some of the students but there are still those select few that just dont seem to care either way. I really want students to get excited to learn and study. I feel like when I was in elementary school everyone got A's and B's. I see so many students failing and getting below average scores. Today I told the students that they were having their Spelling test on Friday and that if every single student got at least an 80 percent on the test then I would have a surprise for them next week. They got excited when I told them that so I am hoping that this is something that could get them motivated to want to study and do well. I also want it to become something that turns into a good habit for each student. I don't want students just doing well because of a reward but because they see the importance in getting good grades. I guess we will see Friday how the students do and if it is something I should continue to do. Perhaps each week I may raise the goal of the test grade being higher.