用简便方法计算45+208+155 23+（159+77） 307+2566×（19×5） 24×25 25×32×125．
直接写得数．= 24÷====﹣==﹣×=
直接写出得数： 3﹣1.2=（0.1）3= 3÷1=×0.4=﹣=×7=+1= 5×÷5×=+×= 21÷3=
直接写得数．×4= 6﹣=÷=×=×=÷=÷=÷=
= 2.5== 1== 1×= 3÷1%==．
×0=×=÷=÷=
= 24÷
=
=
=
=
﹣
=
=
=
﹣1.2=（0.1）3= 3÷1
=
×0.4=
﹣
=
×7=
+1
= 5×
÷5×
+
×
= 21
÷3=
×4= 6﹣
=
÷
=
×
×
=
÷
=
÷
=
÷
=
= 2.5
=
= 1
=
= 1
×
= 3÷1%=
=．
×0=
=
=
=
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