57÷7用竖式计算

……………………………………………

................8 . 1....4....2....8....5....7....
......————————————————————————
7 ）5....7
.........5....6
.........________
...............1.....0
.......................7
............._____________
......................3....0
......................2....8
.....................__________
............................2....0
............................1....4
..........................____________
...................................6....0
...................................5....6
.................................___________
..........................................4....0
..........................................3....5
........................................_____________
................................................5....0
................................................4....9
.............................................___________
......................................................1
这道题的商是位小数，循环节是142857 。