He Juntao's average step length is 0.7 meters. He walked 420 steps from home to school and back. How many meters away is his home from school?
何俊涛的平均步长是0.7米，他从家到学校往返一趟走了420步，他家离学校多少米．
<gadget id="calculator">420 / 2</gadget>
<output>210</output>

<gadget id="calculator">0.7 * 210</gadget>
<output>147</output>

<result>147</result>