求大佬教教

LCD_Write_String(0, 0, "Date:");
LCD_Write_Char(5, 0, year/1000+48);
LCD_Write_Char(6, 0, year%1000/100+48);
LCD_Write_Char(7, 0, year%100/10+48);
LCD_Write_Char(8, 0, year%10+48)
year%10+48为什么要加48