You can buy 3 sweaters for the price of one coat, and one coat costs 420 yuan. How much is a sweater cheaper than a coat?
买一件大衣的钱可以买3件毛衣，一件大衣420元．一件毛衣比一件大衣便宜多少元？
<gadget id="calculator">420 / 3</gadget>
<output>140</output>

<gadget id="calculator">420 - 140</gadget>
<output>280</output>

<result>280</result>