（选做题）有一架天平，只有5克和30克砝码，要把300克盐分成三等分，最少称几次，写出你的称法．
直接写得数 2﹣=×= 20%÷=×30%= 3.5+1.5= 0.5×=
直接写出得数+= 1÷0.25= 3.14×8= 6.3×= 2.4÷=×= 80×40%= 21÷=﹣×5=×18×=
直接写得数+=×12= 1÷5%= 1﹣0.625=
口算==×= 2﹣==×=
直接写出得数．+=×3=××=÷= 50÷1%= 0.33=
=
×
= 20%÷
=
×30%= 3.5+1.5= 0.5×
+
=
= 2.4÷
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×
= 80×40%= 21÷
=
﹣
×5=
×18×
=
+
=
×12= 1÷5%= 1﹣0.625=
=
=
×
=
=
=
×
=
+
=
×3=
×
×
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÷
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