20以内凑十法练习题(每日一练)
.3 + 9 = 3 + 8 = 6 + 6 = 6 + 5 = 9 + 3 = 9 + 2 = 8 + 7 = 8 + 9 = 9 + 6 = 9 + 5 = 9 + 8 = 9 + 9 = 8 +
20以内凑十法练习题(每日一练)