There are 10 children lined up in a column, and the distance between every two children is 1 meter. What is the total length of the column?
有10个小朋友排成一路纵队，每两个小朋友之间相距1米，这路纵队全长多少．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">9 * 1</gadget>
<output>9</output>

<result>9</result>