1、 10-2=8 11-3=8 13-5=8 14-6=8 15-7=8 16-8=8 17-9=810-2=8 11-3=8 12-4=8 12-4=8 13-5=8 14-6=8 15-7=8 16-8=8 17-9=8 14-5=9 14-6=8 14-7=7 14-8=6 14-9=5 14-9=5 14-8=6 14-7=7 14-6=8 14-5=9 10-8=2 11-8=3 12-8=4 13-8=5 14-8=6 15-8=7 16-8=8 17-8=9 17-8=9 16-8=8 15-8=7 14-8=6 14-8=6 13-8=5 12-8=4 11-8=3 10-8=2
2、 10-510-5 11-611-6 12-712-7 13-813-8 14-914-9 10-610-6 11-711-7 12-812-8 13-913-9 10-710-7 11-811-8 12-912-9 10-810-8 11-911-9 10-910-910-210-2 11-311-3 12-412-4 13-513-5 14-614-6 15-715-7 16-816-8 17-917-9 10-310-3 11-411-4 12-512-5 13-613-6 14-714-7 15-815-8 16-916-9 10-410-4 11-511-5 13-713-7 14-814-8 15-915-9 12-612-6 10-1 11-2 12-3 13-4 14-5 16-7 15-6 18-9 17-8 10-? 11-? 12-? 13-? 14-? 15-? 16-? 17-? 18-? 9876543 21 15 - 6 = 915 - 6 = 9 13 - 8 = 513 - 8 = 5 13 - 6 = 713 - 6 = 7 11 - 8 = 311 - 8 = 3 15 - 7 = 815 - 7 = 8