True: 10-5=5, 4+8 =12, 20-8=12, 17-7=10, 13-9=4, 19-4=15, False: 14+4=20, 15+3=19, 15-7=4, 20-6=10, 17+3=19, 12-10=3,

Addition and Subtraction within 20 True or False

排行榜

視覺風格

選項

切換範本

恢復自動保存: ?