In order to control sandstorms and protect the environment, Changshan Township has planted a 15-kilometer-long and 8-meter-wide shelter belt. If poplars are planted with a spacing of 3 meters and a row spacing of 2 meters, how many trees should be planted in this shelter belt?
为治理沙尘暴，保护环境，长山乡种植了一条长15千米，宽8米的防护林带，如果栽杨树，株距3米，行距2米，那么这个防护林带共需植树多少棵？
<gadget id="calculator">15 * 1_000</gadget>
<output>15_000</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">8 / 6</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">15_000 * (4/3)</gadget>
<output>20_000</output>

<result>20_000</result>