（5.5+2.3)×5.6＋2.3×4.4 =5.5×5.6+2.3×(5.6+4.4)=30.8+23=53.80.73×101 = 0.73×(100+1 )= 0.73×100+0.73×1 =73+0.73=73.73 0.25×9.87×4 = （0.25×4 ） ×9.87=9.8776.3×27－76.3×17= 76.3×（27－17）= 76.3×10=763
