Mom bought 4 kilograms of apples for 16 yuan. How much does it cost to buy 7 kg of apples?
妈妈买4千克苹果用了16元．如果买7千克苹果，需要多少元．
<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">4 * 7</gadget>
<output>28</output>

<result>28</result>