Teacher Wang brings a sum of money to buy pens at 12 yuan each, and can buy 14 pens. If he uses this money to buy calculators, he can only buy 4, leaving 4 yuan. How much is each calculator?
王老师带一笔钱买每支12元的钢笔，能买14支．如果他用这笔钱去买计算器的话，只能买4只，还余下4元．求计算器每只多少元？
<gadget id="calculator">12 * 14</gadget>
<output>168</output>

<gadget id="calculator">168 - 4</gadget>
<output>164</output>

<gadget id="calculator">164 / 4</gadget>
<output>41</output>

<result>41</result>