20以内三个数连减（2023-10-27）

20以内三个数连减（2023-10-27）：18-15-2= 12-5-3= 16-12-2= 18-2-1= 19-8-4= 6-2-1= 19-6-7= 15-12-0= 18-5-11= 16-9-2= 15-7-6= 14-8-3= 12-9-1= 10-6-0= 18-1-4= 7-2-0= 9-1-3= 11-2-1= 16-8-2= 12-7-4= 16-2-0= 17-3-7= 13-4-6= 15-3-8= 19-12-3= 14-1-12= 15-5-0= 13-2-10= 17-10-0= 15-8-5= 7-1-4= 15-10-1= 9-2-3= 13-9-2= 19-2-12= 17-9-3= 14-4-7= 16-5-6= 18-6-1= 16-13-2= 18-8-6= 19-9-2= 12-2-5= 17-7-8= 13-3-1= 17-8-4= 19-7-6...