四年级下册数学 小数加减法简便计算

四年级下册数学 小数加减法简便计算


简介:
(1)4.12-1.78-1.22 =4.12-(1.78+1.22) =4.12-3 =1.12 (3)9.08-2.12-1.88 =9.08-(2.12+1.88) =9.08-4 =5.08 (5)52-17.87-12.23 =52-(17.87+12.23) =52-30.1 =21.9 (7)202.02-162.2-37.8 =202.02-(162.2+37.8) =202.02-200 =2.02