1克拉的钻石可能只有0.99克拉？买钻石一定选1.01克拉吗？

bushaoguketiaoxuanzuanshidaxiaodeshihou，bijiaorezhongyu1.01kela、2.01keladengbizhengfenshushaoweidayidiandiandezuanshi，zhuyaoyuanyinshidanxin“1keladezuanshikenengzhiyou0.99kela”。qishizheizhongdanxinwanquanshiduoyude，dajiawanquankeyihaowugulvditiaoxuan“1kela”deng“zhengfenshu”dezuanshi。

1克拉的钻石实际上可能只有0.99克拉吗？

youkenengchuxianzheizhongqingkuang，danwuxuzaiyi。

【guobiaozuanshichengzhongbiaozhun：

1. yongfenduzhibudayu0.0001gdetianpingchengliang。zhiliangshuzhibaoliuzhixiaoshudianhoudi4wei。huansuanweikelazhongliangshi，baoliuzhixiaoshudianhoudi2wei。kelazhongliangxiaoshudianhoudi3weifeng9jin1，qitakehulvebuji。

2. dangshiyongfenduzhibudayu0.00001gdetianpingchengliangshi，zhiliangshuzhikebaoliuzhixiaoshudianhoudi5wei。huansuanweikelazhongliangshi，baoliuzhixiaoshudianhoudi3wei。kelazhongliangxiaoshudianhoudi4weifeng9jin1，qitakehulvebuji。】

zuanshidezhongliangjingquedushikeladanweixiaoshudianhou4wei，erzaizuanshijiandingjigou，duiyuzuanshizhongliangdejinweiyuanze，shiyongdeshi“bashejiuru”。biruyikezuanshichengzhongshujushi0.9998ct，jiuhuixiecheng99cthuozhe0.99ct。ruguozuanshichengzhongshujushi0.9999，caihuixiecheng1.000cthuozhe1.00ct。

suoyishuoruguomaideshi1.00ctzuanshi，qishijizhongliangfanweikenengshi0.9999－1.0008ctzhongderenyiyigezhongliang；

ruguomaideshi1.01ctzuanshi，shijizhongliangfanweijiushi1.0009-1.0098ct。

如果买的1克拉钻石实际是0.999克拉，是不是就吃亏了？

zhongsuozhouzhi1kela=0.2ke，erzuanshizhongliangqueshaode0.001kelajiudengyu0.0002ke，feichangxiao，kenengshouzhizaizuanshishangmoyixia，zhanshangdeyouwuhuichendoubizheigezhong，guanzhuzheiyidianxiaoxijie，henmeiyoubiyao。

买钻石一定选1.01克拉吗？

ruguozijibijiaozaiyizheiyidian，jiuzhijiexuan1.01keladezuanshi，keyibaozhengkendingzai1.00ctzhishang。

qishiwulungia、hrdyijiqitarenhequanweijiandingjigou，zhengshushangchujudeshi1.00kela，neimeyangeyiyishang，zheimeizuanshijiushi1kela，buxuyaoyourenhehuaiyi。jibianyihouzaicichushou，yeshigenjuzhengshushangdezhonglianglaigujia，suoyibingbuxuyaodanxinzheixie。