(1) 6647-1568+568-647+365 =6647-647-1568+568+365 数字要搬家带着符号走 = (6647-647)- (1568-568)+365 添括号 =6000-1000+365 =5365 (2) 2348 - 254- 69+2254- 48- 31 =2348-48+2254-254-69-31 数字要搬家带着符号走 =(2348-48+(2254-254)-(69+31) 添括号 =2300+2000-100 =4200