In my early teaching career which is 30 some years ago. I never have any problem assigning scales to my students. Most of my students can play four octaves ascending and descending smoothly. Ever since the iPad and tablet become popular, I have encountered many difficulties in teaching students scales.  In the past 10 years, I had a hard time to teach scales. Students are either tell me that they lost their scale books, their dog chews on their books, or they just don’t want to play scales. This is the reason why I decided to rewrite these scales for these iPad & tablet generation. My students love to play these scales arrangement. Especially my teen students. Some of my adult students love it as well. Because my adult students feel they can work on their arms and fingers. Normally, I will play with them on another piano. I don’t have to play the same notes. Sometimes, I just play chords. Also, I ask them not to play too slow. I have two teen students who loved these arrangements very much.  One of the teen students who were at the beginner’s level. She loved these scales exercises very much, sometimes, she came into the lesson and play different technique arrangements non stop for the whole half hour lessons. Two months later, I assigned her a boogie type of song that is at the late intermediate level, she accomplished that song beautifully. Because these scales are designed by the patterns, most of my students play without reading at the notes. Therefore, the best thing you can do is to download it in your tablet like Ibook. Have the students read it from the tablet. There are many arguments about teaching scales. I have heard many piano players feel it is not necessary to insist our students to play scales.  Especially for adult students. They are struggling with hands and finger coordination. If they play more scales, it will help them with their fingers and hands coordination. You can give it a try for at least a month and you will feel something is different.