A child took 81 flower seeds and walked on the grass. He walks 1 meter, sows 1 seed; walks 4 meters, sows 3 seeds; walks 7 meters, sows 5 seeds; ... according to this rule, when he has sown all the seeds , how far has he walked?
一个小朋友的手里拿了81粒花种在草地上散步．他走了1米，撒下1粒种子；又走了4米，撒下3粒种子；再走7米，撒下5粒种子；…照此规律，当他把所有的种子撒完的时候，他走了多少路？
<gadget id="calculator">9 * 1</gadget>
<output>9</output>

<gadget id="calculator">9 * 8</gadget>
<output>72</output>

<gadget id="calculator">72 / 2</gadget>
<output>36</output>

<gadget id="calculator">36 * 3</gadget>
<output>108</output>

<gadget id="calculator">9 + 108</gadget>
<output>117</output>

<result>117</result>