Xiao Ming bought a schoolbag with a 30% discount, saving 21 yuan. How much did he actually pay for the schoolbag?
小明以7折优惠买了一个书包，节省了21元，他买这个书包实际付了多少元．
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">21 / (3/10)</gadget>
<output>70</output>

<gadget id="calculator">70 - 21</gadget>
<output>49</output>

<result>49</result>