i designed a two digit up counter using 2 x 4511 and 2 x 74192. my schematics are as followed, in multisim it is fully functionally working but when i build it out there is a problem, the number do not increase in sequence but rather jump all about, i found the problem which is the 74192 but i do not really know why. it does not output as expected ( 0000 , 0001 , 0010 , 0011 ) but rather in the same sequence as what i'm seeing on the led.. i would be delighted if some one can tell me the flaw in my design or the reason why my counter is acting like this! and yes my Vcc and Vdd are connected except my inputs A-D. this is urgent D: i have been dwelling on it for 4 days please help! and sorry if the answer is just in front of me because it's only my first year in electrical engineering. all helpful comments that will help better my understanding would be appreciated!