先估一估，填在括号里，再笔算，最后用计算器验算．436×29 264×13= 27×336= 155×46= 38×142= ．
直接写得数+=﹣=×=÷=÷= 20×=×5=÷5=
直接写得数． 9.3×7.9≈ ×0.5=1×=+=÷2=×5÷×5= 0.42= 0.561×100=
直接写出得数+=÷45%= 30﹣29.02=﹣+= （×12= 1.25××8= 8.2+0.54+0.46=÷﹣=
直接写出得数=== 0.9+99×0.9= 8.8÷0.2====
直接写出得数． 2﹣= 0÷÷=+3= 134﹣34=×=÷×=﹣= 4×=
+
=
﹣
=
×
=
÷
=
÷
= 20×
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×5=
÷5=
×
=
+
=
÷2=
+
=
÷45%= 30﹣29.02=
﹣
+
=
×12= 1.25×
×8= 8.2+0.54+0.46=
÷
=
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= 0.9+99×0.9=
=
=
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= 0÷
÷
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+3= 134﹣34=
×
=
÷
×
﹣
= 4×
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