不进位加法和不退位减法
第3课时
5 + 11 = 13 + 4 = 20–10 =
19 - 8 = 18 – 5 = 12 + 7 =
15 –3 = 5 + 14 = 6 + 12 =
11 + 5 = 17 – 3 = 15 - 5 =