The numbers on the AM dial of a radio represent the frequencies of radio stations in kilohertz (kHz). The AM band in North America ranges from 520 kHz to 1710 kHz. Each AM radio station is assigned a specific frequency within this range. For example, a radio station that broadcasts at 1030 kHz would be found at the "1030" mark on the AM dial.
FM radio:
The numbers on the FM dial of a radio represent the frequencies of radio stations in megahertz (MHz). The FM band in North America ranges from 87.9 MHz to 107.9 MHz. Each FM radio station is assigned a specific frequency within this range. For example, a radio station that broadcasts at 91.1 MHz would be found at the "91.1" mark on the FM dial.
In addition to the frequency numbers, some FM radio dials also display the call letters of radio stations. The call letters are a unique identifier assigned to each radio station by the government. For example, the call letters of the radio station that broadcasts at 91.1 MHz might be "KRCL".