YOU SAID:

My brother ate 5 and a half hotdogs yesterday

INTO JAPANESE

私の兄は昨日5つ半のホットドッグを食べました

BACK INTO ENGLISH

My brother ate five and a half hot dogs yesterday

INTO JAPANESE

私の兄は昨日5匹半のホットドッグを食べました

BACK INTO ENGLISH

My brother ate five and a half hot dogs yesterday