Xiao Ming inserts a bamboo pole into the water, the part that enters the water is 30 cm, then he turns the bamboo pole upside down, and then inserts it into the water, the part that is not wetted by this time is 40 cm, how many decimeters is this bamboo pole long?
小明把一根竹竿插入水中，入水部分是30厘米，然后他把竹竿倒过来，再插入水中，这时没沾水的部分是40厘米这根竹竿长多少分米？
<gadget id="calculator">30 + 30 + 40</gadget>
<output>100</output>

<gadget id="calculator">100 / 10</gadget>
<output>10</output>

<result>10</result>