用简便方法计算,并写出简算过程.246+78.5+254+21.50.125×2.5×32036×(23-14+19)724×0.2+1724÷5.-数学
题文
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答案
(1)246+78.5+254+21.5 =(246+254)+(78.5+21.5), =500+100, =600; (2)0.125×2.5×320 =0.125×2.5×80×4, =(0.125×80)×(2.5×4), =10×10, =100; (3)36×(
=36×
=24-9+4, =19; (4)
=
=(
=1× |