Li Dong’s family bought a new computer and spent 4,200 yuan, which is 1/15 less than last year. How much did Li Dong spend less on the computer than last year?
李冬家新买了一台电脑，花了4200元钱，比去年节省了(1/15)，求李冬买电脑比去年少花了多少钱？
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 - (1/15)</gadget>
<output>14/15 = around 0.933333</output>

<gadget id="calculator">4_200 / (14/15)</gadget>
<output>4_500</output>

<gadget id="calculator">4_500 - 4_200</gadget>
<output>300</output>

<result>300</result>