怎样简便就怎样算.256+199 102×4.57.8×6.9+2.2×6.9 24×2.5．
神机妙算细又巧！（写出简算过程）×9+（+）×15×17×12﹣÷×+×+．
×3.6+×0.75．
脱式计算．能简算的要简算 1.26÷0.4÷31.5 18﹣（+）×1051.25×32×0.25．
3.7×0.172+0.37×8.28．
6.4×4.2+4.2×4.6﹣4.2．
+
）×1051.25×32×0.25．
×9+
（
+
）×15×17
×12﹣
×
+
×
×3.6+
×0.75．
粤公网安备 44130202000953号