Construction workers prepare a concrete with cement, sand, and stones in a ratio of 2:3:5. How many kilograms of cement are needed to prepare 8000 kilograms of this concrete?
建筑工人把水泥、沙子、石子按2：3：5的比例配制一种混凝土．配制8000千克这种混凝土，需要水泥多少千克？
<gadget id="calculator">2 + 3 + 5</gadget>
<output>10</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">8_000 * (1/5)</gadget>
<output>1_600</output>

<result>1_600</result>