A crayon is originally 10 cm long, but 7 mm is used up, how many mm is left?
一枝蜡笔原来长10厘米，用去了7毫米，还剩多少毫米长？
<gadget id="calculator">10 * 10</gadget>
<output>100</output>

<gadget id="calculator">100 - 7</gadget>
<output>93</output>

<result>93</result>