Zhang Dong left home to go to school in the county seat. After walking at a speed of 50 meters per minute for 2 minutes, he realized that he would be 8 minutes late if he kept walking at this speed, so he speeded up and walked an extra 10 meters per minute. At that time, there are still 5 minutes before class, how far is the distance from Zhang Dong's home to the school?
张冬离家去县城上学，他以每分钟50米的速度走了2分钟后，发觉按这个速度走下去就要迟到8分钟，于是他加快了速度，每分钟多走10米，结果到校时，离上课还有5分钟，张冬家到学校的路程是多少？
<gadget id="calculator">50 * 8</gadget>
<output>400</output>

<gadget id="calculator">60 * 5</gadget>
<output>300</output>

<gadget id="calculator">400 + 300</gadget>
<output>700</output>

<gadget id="calculator">700 / 10</gadget>
<output>70</output>

<gadget id="calculator">70 + 8</gadget>
<output>78</output>

<gadget id="calculator">50 * 78</gadget>
<output>3_900</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">3_900 + 100</gadget>
<output>4_000</output>

<result>4_000</result>