Use puzzles and logic games at the beginning of each class to spark your students' interest. Put a riddle or brain teaser on the board and let students spend five or 10 minutes each day trying to figure it out. You can start with something simple, such as asking students to calculate how many seconds they have been alive. Move on to brain teasers, many of which can be found online.
Let students teach other in order to encourage participation. Organize the class into small groups and make each responsible for introducing a new unit to the class. Have groups become experts in their topics by reading ahead in the textbook. See how much they can learn on their own and impart to the rest of the class. Supplement their presentation with your own lessons and tips.
Play games in the classroom, whether on Friday afternoon as a reward, or as part of the daily routine. Find board games that require students to use math skills, such as arithmetic and logic. Use games such as "Monopoly" and "Mastermind."
Teach real-world applications of math problems to middle school students. Make arithmetic seem less abstract and more interesting by having students imagine their adult lives and plan a budget. Ask students to pair up and draw up a plan for a start-up business, complete with budget and sales projections.