Final answer:
Sherman receives a WABAC machine from Mr. Peabody instead of a phone for his school adventures, which allows them to travel through time.
Step-by-step explanation:
When Sherman gets ready to go to his first day of school, instead of a phone, Mr. Peabody gives Sherman a WABAC (pronounced "way-back") machine, which is a fictional time machine that they use for their adventures. The WABAC machine allows them to travel through time and witness, participate in, and alter historical events. This occurs in the animated feature film and television series featuring the characters Mr. Peabody and Sherman.