Our classmates recycled 2.5 kilograms of waste paper. How many kilograms of recycled paper can be produced from these waste papers? (Recycling 1 kg of waste paper can produce 0.84 kg of recycled paper.)
我们班同学回收了2.5千克废纸，这些废纸可生产多少千克的再生纸？(回收1千克废纸，可生产0.84千克的再生纸．)
<gadget id="calculator">2.5 * 0.84</gadget>
<output>2.1</output>

<result>2.1</result>