687+456=※704﹣487=※568+946=840﹣473=457×5=506×6=※56÷9=20÷7=
68×34+68×67﹣68.
26×49+26.
用简便方法计算:24.6×4.6+246×0.44+24.6.
①25.74﹣2.36﹣7.64 ②0.75×0.25×4③8.4÷0.25÷4 ④2.8×3.6+1.4×2.8.
96×101.