Xiaohua's father runs in the morning to exercise. When he runs to 300 meters from the midpoint, the ratio of the distance covered to the whole journey is 3:5. How many meters is the whole journey of Xiaohua's father running?
小华的爸爸旱晨跑步锻炼身体，当跑到距中点300米时，已走路程与全程的比是3：5，小华爸爸跑步的全程是多少米？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">300 / (1/10)</gadget>
<output>3_000</output>

<result>3_000</result>