Xiaohong goes from home to school, if she walks 80 meters per minute, she can arrive at school in 10 minutes. In order not to be late, she must arrive at school in 8 minutes. How much more meters should she walk per minute? (Solve with ratio)
小红从家到学校，如每分走80米，10分可以到校．为了不迟到，她必须用8分赶到学校，每分应多走多少米？(用比例解)
<gadget id="calculator">80 * 10</gadget>
<output>800</output>

<gadget id="calculator">800 / 8</gadget>
<output>100</output>

<gadget id="calculator">100 - 80</gadget>
<output>20</output>

<result>20</result>