The length of the part is measured as 50 mm on a precision part drawing with a scale of 4:1. What is the actual length of the part?
在一张比例尺为4：1的精密零件图纸上量得零件长50毫米，该零件实际的长为多少．
<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">50 / 4</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>