In a stationery store, 2 mechanical pencils sell for 7 yuan, and 3 fountain pens sell for 18 yuan. Teacher Zhang is going to buy 10 mechanical pencils and 21 fountain pens. How much will it cost in total?
文具店中2支自动铅笔卖7元，3支钢笔卖18元，张老师准备购买10支自动铅笔和21支钢笔，一共需要多少钱？
<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">(7/2) * 10</gadget>
<output>35</output>

<gadget id="calculator">18 / 3</gadget>
<output>6</output>

<gadget id="calculator">6 * 21</gadget>
<output>126</output>

<gadget id="calculator">35 + 126</gadget>
<output>161</output>

<result>161</result>