五年级上册数学 期末小数简便计算复习

五年级上册数学 期末小数简便计算复习


简介:
399.6×9-1998×0.8 =399.6×9-1998×2×0.4 =399.6×9-399.6×4 =399.6×5 =1998 12.9÷0.72+43.5÷3.6 =(12.9×5)÷(0.72×5)+43.5÷3.6 =64.5÷3.6+43.5÷3.6 =(64.5+43.5)÷3.6 =30 49.5×13.5-0.5×49.5+50.5×13 =49.5×(13.5-0.5)+50.5×13 =49.5×13+50.5×13 =(49.5+50.5)×13 =1300