两个加数的百位与百位、十位与十位、个位与个位可以互换
437+589 = 1026
246+789 = 1035
264+789 = 1053
473+589 = 1062
324+765 = 1089
432+657 = 1089
346+752 = 1098
423+675 = 1098
347+859 = 1206
426+879 = 1305
624+879 = 1503
743+859 = 1602