题目内容
【题目】用简便方法计算。
①16.3×9+16.3
②98×0.51
③1.25×16×2.5
④(0.8+8)×12.5
⑤5.2×10.1
⑥2.5×3.7+63×0.25
【答案】①163
②49.98
③50
④110
⑤52.52
⑥25
【解析】
①16.3×9+16.3
=16.3×(9+1)
=16.3×10
=163
②98×0.51
=(100-2)×0.51
=100×0.51-2×0.51
=51-1.02
=49.98
③1.25×16×2.5
=1.25×(8×2)×2.5
=(1.25×8)×(2×2.5)
=10×5
=50
④(0.8+8)×12.5
=0.8×12.5+8×12.5
=10+100
=110
⑤5.2×10.1
=5.2×(10+0.1)
=5.2×10+5.2×0.1
=52+0.52
=52.52
⑥2.5×3.7+63×0.25
=2.5×3.7+6.3×2.5
=2.5×(3.7+6.3)
=2.5×10
=25
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