rough out; round down; round off; round out

rough * out +
He'll just rough out the whole picture and I can do the details. (他只要概略地畫出草圖,我就能把細節補上)
Professor Chen has roughed out a few basic ideas. (陳教授已勾勒出一些基本構想)

round * down +
捨棄尾數把 (數字、價格等) 調低或降低為整數
A charge of $10.11 will be rounded down to $10. (把 10.11 美元的費用下調為整數 10 美元)

round * off +
圓滿完成 (或結束);把尖角磨圓
She rounded off the tour with a concert at Taipei Arena. (她在台北小巨蛋舉行的音樂會圓滿地結束了這次巡迴演出)
He rounded off the edges with a piece of sandpaper. (他用砂紙將邊緣磨圓)

round * out +
完成 (某事)
More research is needed to round out the doctoral/master's thesis. (需要更多的研究來完成這篇博士/碩士論文)