A 15th-century rhyme that is still in use...

Thirty days hath November
April June and September
Of eight-and-twenty is but one
And all the remnant thirty one.

The oldest known version of this is in a 15th-century manuscript, and I still recite a slightly modernised version to myself when trying to sort the 30s from the 31s.

It is a powerful demonstration of why so much early modern "technical information" is put in verse - while oral transmission and memory remains important, even if the material is also being committed to print, and other media - Thomas Tusser, author of a phenomenally successful book of housewifery, recommends that the "comely decked guest-room" be decorated with painted verses, such as:

"The sloven and the careless man, the roinish [scabby] nothing nice,
To lodge in chamber comely decked, are seldome suffered twice."

A cobbler too, was expected to be able to readily "reckon up his tools in rhyme" - surely a good way of checking nothing was missing.

(From Jones, M. "Such pretty things would soon be gone': The Neglected Popular Verse 1480-1650", in Hattaway (ed) A Companion to English Reniassance Literature and Culture, Blackwell, 2000 p. 457. This is a mammoth tome, but has some really excellent stuff in it. I'm using it to try to ensure I haven't missed anything important in various projects relating to the period.)