How to do the ninth question in the second unit of the second volume of the first grade mathematics of Jiangsu Education Edition?
First, oral calculation. (20 points)11+7 =17-5 =19-8 =16-7 = 8+5 =14-9 = 20+0. 438+08-7 =14-6 =15-8 =15+4 = 4+8 = 9+9 =13-5 = 8+9 = 2. Mark "√" in the right picture and "×" in the wrong question. (12 point) 13-6...7378