①8+=15 ②9+=14 ③+9 =15
④15– 8= ⑤14–9 = ⑥15 – 9 =
⑦15–7= ⑧14–5 = ⑨15-6 =
17 – 4 = 6 +5 = 7 +6 = 18 – 6 =
13 – 8 = 8 +7 = 8 +5 = 12 – 7 =