20以内口算题600题

23-19 =5+16 =17+4 =19 + 5 =9+4 =13 — 7 =9 + 4 =7 + 9 =9 + 9 =22 — 7 =9 + 8 =7 + 7 =12-6 =10-2 =8 + 7