小學(xué)五年級奧數(shù)題:簡便運算

字號:

657-(269+357)+169
    答案與解析:
    657-(269+357)+169
    =657-(357+269)+169
    =657-357-269+169
    =300-(100+169)+169
    =300-100-169+169
    =200-169+169
    =200