This excellent idea is ideal for helping children to memorize Maths facts. It could also be used in other subject areas.

Have a student take a stack of flashcards (addition, subtraction, multiplication, or division) and read them into a tape recorder.  There should be a pause between the problem and the answer of about 3 seconds.

For example, "3 x 4 = (pause) 12."

This is done until all flashcards have been used.  The student can play back the tape and try to beat him/herself to the answers.  My students love this activity so much they often want to take it in their vehicles.  Some parents also like to put it on as the children are settling down for bed.