He used object teaching, which means when teaching the teacher should proceed gradually from the concrete objects to the abstract and complex material.
That being said, the first palatalization must have proceeded gradually:
Technological development proceeded gradually, and outdated equipment continued to be used as long as possible.
The rail journey time could be hugely shortened by construction of a tunnel; work began in March 1873 and proceeded gradually through the 1870s.
We will gradually proceed to more sophisticated locks from here.
Restoration has been gradually proceeding since 1987, and it was declared a nature preserve in 2000.
The gulf is usually frozen from late November to late April; the freezing starts in the east and gradually proceeds to the west.
Like many others, too, I also advocate proceeding gradually.
She proceeds gradually, guided by intuition; the result is a complex amalgamation of preparation and instinct, order and chance.
The centers make their appearance at the upper parts of the segments, and proceed gradually downward.