凑十法-破十法-练习题
凑十法练习题.9 + 6 = 9 + 5 = 9+ 4 =9 + 3 = 9 + 2 = 9 + 7 =9 + 8 = 9 + 9 = 8 + 8 =8 + 7 = 8 + 9 = 8 + 6 =8
凑十法-破十法-练习题