|
| (1)304×8, =(300+4)×8, =300×8+4×8, =2400+32, =2432; (2)179×24, =(180-1)×24, =180×24-1×24, =4320-24, =4296; (3)602×91, =(600+2)×91, =600×91+2×91, =54600+182, =54782; (4)[236-(143+47)]×2, =[236-190]×2, =46×2, =92; (5)15×(420÷28+12), =15×(15+12), =15×27, =405. |
关注公众号回复:奥数答案
即可免费获得密码查看答案

[ ]