for children or adults, general or math specific, school/university/doctorate context or just plain how to make things understood? Because the latter is basical

for children or adults, general or math specific, school/university/doctorate context or just plain how to make things understood? Because the latter is basically just what mathematics should be, see http://etymonline.com/index.php?term=mathematic http://etymonline.com/index.php?term=mathematic