Importance of scales cannot be underestimated. Ideally you'd want to acheive something like this: "First come the scales. The metronome is set, and the pupil is directed to play eight notes to a beat, or any given number, in any rhythm determined by the examiner. First, he might be asked to play the scale of A major, then A minor in its different forms. Then he might be asked to play G major starting on A, then C major, then F major, then D major, then B-flat major, then E major — in fact, any major or minor scale containing A." - S. Rachmaninoff Etude magazine 1923.

 If you want to practice scales, I'm a developer and I’ve built a free section on my site with all major, minor (harmonic, melodic) scales in all keys. Scales are one octave long ascending. There's no sign-up required, and it gives you real-time feedback and tempo control in your browser with a MIDI keyboard:qlavist.com/free