SOURCE

		<div class="box1 clearfix">
			<div>111</div>
			<div>222</div>			
		</div>

*{margin: 0;padding: 0;}	
			.box1{border: 1px solid red;width: 100%;height:300px}			
			.box1 div{box-sizing: border-box;border: 1px solid blue;}
			.box1 div:nth-of-type(1){
				width: 100px;
				height: 100px;
				float: left;
			}
			.box1 div:nth-of-type(2){
				overflow: hidden;
				height: 100px;
        width：1100%
			}