There were 258 books in the school library, 209 of which were damaged and cleared, and 104 books were donated by the students on Children's Day. How many books are there in the school?
学校图书室原有藏书258册，有209册破损清除了，六一儿童节时同学们又补捐了104册，学校现有图书多少册？
<gadget id="calculator">258 - 209</gadget>
<output>49</output>

<gadget id="calculator">49 + 104</gadget>
<output>153</output>

<result>153</result>