用简便方法计算下面各题.(1)(15+27)×5×7(2)99989+9989+989+13(3)44445×1.25(4)231÷231231232.-数学
题文
用简便方法计算下面各题. (1)(
(2)999
(3)444
(4)231÷231
|
答案
(1)(
=
=7+10, =17; (2)999
=(1000-
=(1000+100+10)-
=1110-(
=1110; (3)444
=(444+
=444×
|
题文
用简便方法计算下面各题. (1)(
(2)999
(3)444
(4)231÷231
|
答案
(1)(
=
=7+10, =17; (2)999
=(1000-
=(1000+100+10)-
=1110-(
=1110; (3)444
=(444+
=444×
|