4m等于几dm和900mm等于几cm?

4m等于几dm和900mm等于几cm? 4m 等于几dm 25cm等于几mm? 1.2m等于几dm 1尺等于几cm（m或dm）? 126dm等于几分之几m 800mm等于几m 1cm²等于几m²1mm²等于几m² 1cm²等于几dm² 1um等于多少nm ,cm,km,mm dm,m 5m等于多少dm 4cm等于多少dm 5毫米等于几厘米?5mm=几cm 25cm等于（）m等于几分之几米 dm的3次方等于cm的几次方 3.5mm等于几厘米 1.5mm 等于几厘米 1000mm等于几米 1mm等于几um?