Singing is fun. It is useful to get students to hear (I play it) and then sing the scale before they play it. I want them to hear it and internalise the sound. They can sing it and then try to play what they hear, enjoying intervals and learning them intuitively.
As well as knowing a pattern for a scale, with tones and semitones, experiment singing around the scale, finding out for themselves, what sounds good or not!