A precision part is 3mm long. If it is drawn on a drawing with a scale of 15:1, how many centimeters should it be drawn?
一种精密零件长3mm，把它画在比例尺是15：1的图纸上，应画多少cm．
<gadget id="calculator">15 / 1</gadget>
<output>15</output>

<gadget id="calculator">15 / 10</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">3 * (3/2)</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>