Xiao Ming bought a "Four Sages" fighting top. After counter-offering, he paid 7 yuan, which was 3 yuan cheaper than the original price. How many percent was the actual price of the fighting top cheaper than the original price?
小明买了一种"四圣"战斗陀螺，经过还价后，付款7元钱，比原价便宜了3元钱，买战斗陀螺的实际价钱比原价便宜了百分之几？
<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>