(1) 千克=5000克,4000千克= 吨.(2)2kg= g;8kg= g; 吨=2000kg;3000g= kg;6000kg= 吨; kg=5000克.
9000﹣9= ×9.
计算:1.25×+1×﹣125%×= .
计算:5.62×49﹣5.62×39+43.8= .
计算:197×198﹣196×199= .
计算:7.816×1.45+3.14×2.184+1.69×7.816= .