一个三角形交通标志,它的底是8分米,高大约是7分米,如果给它的正反两面涂上油漆,涂漆的面积大约是多少平方分米?
用简便方法计算.
简算 2.25×+1.75×+0.62.5×(1.9+1.9+1.9+1.9)
简算 4.5×25%+1.3×+2.2×0.255.02﹣1.37﹣2.63×40﹣÷.
简算: 3.61÷+6.39×0.25×32×0.15 8×+8×+8 3﹣2+5﹣1.
怎样简便怎样算. 105×(+)(2.76+3.06÷)×2.2 2.5×4.3+2.5×4.7+2.5(﹣25%+)÷×.