The cafeteria bought 40 kilograms of tomatoes and spent 800 yuan. If the price per kilogram of tomatoes drops to half of the original price, how many kilograms of such tomatoes can be bought with 800 yuan?
食堂买来40千克西红柿，用去800元．如果每千克西红柿的价钱降到原来的一半，那么用800元可以买多少千克这样的西红柿．
<gadget id="calculator">800 / 40</gadget>
<output>20</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">800 / 10</gadget>
<output>80</output>

<result>80</result>