How do i teach my preschooler - is it some form of disability or a different...

[Hamzay]

...learning style? Hi there,
i'm a mom of 4 yr ol twin boys and both r hale ,healthy n typically naughty.

they've been going to a pre school and have learnt their abç s and numbers 1 to 10 and rhymes etc - also learning to write on dotted lines different strokes etc.

in school they have also done oral numbers upto 30. we asked our sons to recite and the first one recited all so well with few mistakes but picked it up once we corrected him.
my second twin told 1 to 10 perfectly - then continued to say 11 , 14 , 16 , 17 , 18, 19.
we corrected him - and told him to repeat - after 10 it wuz again 11,14,16 !!
i taught him again to include 12, 13 also - he agreed - and proceeded to say 11,14,16 again!
again and again i taught him - but to no avail - he repeated what i said when i taught him - then when i ask him wot comes after 11 - he says 14 !!!
i gave up and my husband took over to teach him - inspite of repeated efforts, making him count in fingers, making the connection as two is to twooelve
but still - no avail - we both are stumped as to how to teach him - how to get him learn this - why is he so stuck on this?
now we cant help but lose our temper on this

he is usually a very bright child - a little hyperactive, always upto something, very very distracted , but even then is aware of everything going on around him - very sharp to pick uyp what stuff we talk - but cant understand a simple pattern of numbers.
he loves to imitate adults n likes to be authorative and be the best - he is a very very active child and kind at heart n plays well with his brother.

i 'm at loss for thoughts - is this a learning disability or maybe has a different style of learning - if so please help me identify it and also please gimme a solution as to how to teach him after 11 comes 12 and 13 - its been 3 days - after i teach him - and when i ask him he tells me the same answer and i loosing my wits at this stage !

HELP!