简便运算(1)13×23+0.34×27+13×13+57×0.34(2)13+34+25+57+78+920+1021+1124+1935(3)2009÷200920092010.-数学
题文
简便运算 (1)13×
(2)
(3)2009÷2009
|
答案
(1)13×
=(13×
=(
=1×13+1×0.34, =13+0.34, =13.34; (2)
|
题文
简便运算 (1)13×
(2)
(3)2009÷2009
|
答案
(1)13×
=(13×
=(
=1×13+1×0.34, =13+0.34, =13.34; (2)
|