口算.
直接写得数.345+233= 45×11= 527﹣398= 235﹣47﹣53=0.78+1.32= = 2.56+1.4= 1.9×4×0.5=3.67÷100= 3.25×1000= 0.125×0.8= 3.6+2.8+6.4=6.08×304≈ 4838÷61≈ 15﹣2.55= == = = =
直接写出得数:578+216= 18.25﹣3.3= 0.99×9+0.99= 3.2﹣= 2÷3=2×= ×8.1= 1×8+1×2= += 21÷7=
直接写得数:728﹣299= 0.125×0.125= 6÷= ××0= 24×(﹣)=÷5= += 0.1×20%= (0.8﹣0.5)÷0.5= 3×6÷3×6=
直接写出得数67+303= 50﹣10.91= 0.8×10= == 24×50%= 6÷= =5.6÷0.7= = 98×99≈ 562÷80≈
口算:223﹣99= ; 24÷0.04= ; 0.9+99×0.9= ; 25×4÷25×4= ;7.5+0.25= ; = ; = ; = .