Problem: My child does not always notice mistakes during practice.
Try these:
Rhythm is the foundation of good music-making. Before trying to play any notes in a new piece, ask your child to clap the rhythm several times. Break the piece into chunks and clap smaller bits. Look for patterns where the same rhythm repeats.
Use a metronome to establish a steady beat. Have your child clap the rhythm of the music along with the metronome. Now have your child play the music along with the metronome. Start with a slower metronome speed and increase it only when your child can play the rhythm accurately.
Use a digital recorder (physical or software), Garageband, or your phone to record your child playing. Have your child listen to the recording. Ask, "If you were the teacher, what advice would you have for the student who played this?"
Use ScoreCloud to record your child playing. Click the "Analyze" button in ScoreCloud. Have your child look at the notes and rhythms in the music notation it produces to see if they are the same as what he or she was trying to play.