生活中有许多互相平行的线,你能举例说明?
用简便方法计算下列各题.
137+86+63254+(524+146) 262﹣186﹣14
381﹣199228+107323﹣(223+65)
178+297168+249+132+451694+238﹣594.
下面各题怎样算简便就怎样算.
36×1990.54×1.75+8.25×0.542.5﹣÷
﹣
÷
.
75+44+125+66+568×5×125×40
78×45+21×45+4535×98.
简便计算.
8.2×99+8.28.8×12.5 0.78×9.9 12.5×3.4×0.84.5×13.6+55×1.36.
简便运算
(1)4.38﹣2.85+3.62﹣5.15
(2)0.25×1.9×0.5×4.