Teacher Mao needed a 36 cm long iron wire to do the experiment. He cut half of a wire, and then cut another 6 cm, which just met the requirements of the experiment. How long is this wire?
茆老师需要一根长36厘米的铁丝做实验，他将一根铁丝剪去一半，然后再剪去6厘米，正好符合实验要求．原来这根铁丝有多长？
<gadget id="calculator">36 + 6</gadget>
<output>42</output>

<gadget id="calculator">42 * 2</gadget>
<output>84</output>

<result>84</result>