John had no formal education, but was given the rudiments by a neighbour, who taught him to read and write and to do basic sums. 

Mercer was a willing pupil, and he recorded in his autobiography that he used to practice his 'ab, eb, ib, ob, ub' wherever he was. 

Blenkinsop had got him as far as long division when he moved from Oakenshaw to Broad Oak.

John Lightfoot was exciseman at Oakenshaw. At that time, there was a tax on all printed calicoes, and Lightfoot had to see that it was paid correctly. 

He frequently visited Great Harwood and got to know the young Mercer. He had tremendous influence over Mercer, and taught him higher mathematics. 

He later moved from Oakenshaw to Broad Oak, where he continued to befriend Mercer, teaching him and his own sons.

The picture on the right is a copy from a horn book showing the "ab, eb, ib, ob, ub", which was part of the early teaching of letters

Mercer taught himself to read music, first taking a hymn tune he knew and working out how the music followed the variations in the notes. 

He then went right through the hymnbook, keeping the tune he was learning pinned to his handloom.