Scales are a great way to develop finger strength and dexterity. However, with standard fingering (eg right hand 123,1234,123,12345 - ascending) finger 5 gets a raw deal over 2 octaves, whilst 123 gets used EIGHT times if ascending and descending. Therefore an exercise using only 4 and 5 or 3,4,5 is good. Eg start on a high C and play cba. bag, agf, gfe, fed, using 345. Do it in short doses though! Once at the start of practice and perhaps at the ned of practice as well.
Piano and keyboard teacher based in Eccleston, south Lancashire, England.