Xiaoxin's home is 850 meters away from the school. One morning, when she went to school from home, she realized that she had forgotten to bring her math books when she was halfway through the journey. So she went home to get the book and went to school again. About how many meters did Xiaoxin walk to school this morning?
小欣家离学校850米，一天早晨，她从家去学校上学，大约走到总路程的一半时，发现忘记带数学书．于是她又回家拿书，再去学校．这天早晨，小欣上学大约一共走了多少米？
<gadget id="calculator">850 * 2</gadget>
<output>1_700</output>

<result>1_700</result>