Challenge your students to create a board game involving decimals. Give examples of things they could do such as dividing one large move into ten smaller ones or having two different colored dice that each stand for a different place after the decimal. Provide construction paper to use as cards and cardboard to use as a game board. Divide students into groups of three or four people each to create the game as a group project and to play test it. They should write out the instructions and then pass it to another group to play when they are finished.
Bring in a tap dance teacher or take your students on a field trip to a dance studio. Have the teacher teach them basic tap dance and then talk to them about how those steps relate to decimals. For some students, the physical act of dancing will give them a greater understanding of decimals than experiencing it on paper. Tap dance in particular focuses on having to learn how to tap your foot in fractions of a beat.
Bring in a music teacher and teach children how to read music. After each lesson on reading sheet music, talk about how the notes could be converted to decimals. In 4/4 time, a whole note represents 1.0, a half note represents 0.5 and a quarter note represents 0.25. Eventually give them a sheet of music and have them translate it into decimals. More advanced students can move on to different time signatures and translate how the decimals would change in different time signatures.
Ask for 11 volunteers from your class. Pass out pieces of paper on which you have written one digit between 0 and 9 and one with a decimal point. Write these symbols large enough so they can be seen from the back of the classroom. Then say a number with a decimal out loud and tell the students to arrange themselves in the correct order. For example, you might say 41.58 out loud and the five students holding those symbols would have to arrange themselves in that order. If they do so correctly, have the rest of the class applaud. Then have those students hand their cards to someone in the classroom that has not yet been part of the human decimal machine.
Money is a popular way to teach decimals as the practical value of understanding at least the ones' and tens' places becomes immediately clear. Hand out play money throughout the day as rewards for answering questions, sitting quietly or turning in an assignment. Make sure that you hand out play coins as well as dollars. At set times throughout the day -- possibly right before recess, at lunch time or right before the end of the day -- have students count how much money they have and write it using the proper decimal place. At the end of each day, they can turn their money in after recording in your workbook the total amount they have. Give bonuses for each correct amount recorded. At the end of the week, let students buy rewards with their money. Set the amount for rewards so that decimals must be used and students must add and subtract using decimals.