小海的妈妈晚饭后出去散步,他向西走出50米,再向北走出50米,然后又向东走出50米,这时他离家 米.
脱式计算与简便运算= = = = 6﹣×﹣= 〔1﹣(﹣)〕÷= = = 5+3.6×2.5÷0.48= = = = 3.6×2÷16.9÷(3×1.1 6)×1.3= +++…+= .
=()×12=
546﹣398457+199 2.2×1015.4×99+5.432×0.125×25 .
计算:的值为多少?
脱式计算,能简便的简便. 4.2﹣1.38+5.8﹣3.620.125×0.25×32 2