For example, Matter 1 – Damp and mould growth, Matter 2 – Cold, and Matter 3 – Heat are more common problems than Matter 27 – Explosions, and Matter 29 - Structural collapse.
Er enghraifft, mae Mater 1 - Lleithder a thyfiant llwydni, Mater 2 - Oerfel a Mater 3 - Gwres yn broblemau mwy cyffredin na Mater 27 - Ffrwydradau a Mater 29 - Dymchwel strwythurol.