in lesson 1.13 numbers- the y does not start until trenta but in lesson 1.14 telling the time 12:30 doce y media- why not just say doce media ?

Hello Larry...in spanish we tell the numbers in a way and the hour in a diffrent way. As you already said , the "y" (which would be like the "and" but in spanish) is used with the 30 and above numbers.... Now, "media" is not a number its actually a word...which means "half"...you would never say "It is twelwe half"...you would probably say "It is twelve and a half" or simply "It is twelve thirty" or something similar. You could also say "Doce y media" or "Doce treinta" (yes, without the "y") or "Doce y treinta" (with the "y").