苏教版数学一年级下册 20以内退位减法 单元复习11-9 12-9 13-9 14-9 15-9 16-9 17-9 18-9 11-8 13-8 14-8 16-8 17-8 12-7 14-7 16-7 11-6 13-6 15-6 12-5 14-5 11-4 13-4 12-3 11-211-9 12-9 13-9 14-9 15-9 16-9 17-9 18-9 11-8 12-8 13-8 14-8 15-8 16-8 17-8 11-7 12-7 13-7 14-7 15-7 16-7 11-6 12-6 13-6 14-6 15-6 11-5 12-5 13-5 14-5 11-4 12-4 13-4 11-3 12-3 11-211- 8 11- 6 12- 8 12- 6 13- 8 13- 6 14- 8 14- 6 11- 4 11- 3 11- 2 12- 4 12- 3 13- 4 15- 8 15- 6 16- 8 17- 8 11- 9 12- 9 13- 9 14- 9 15- 9 16- 9 17- 9 18- 9 11- 7 12- 7 13- 7
