There are 378 boys and 346 girls in a certain elementary school. 390 people are known to have participated in the tour, how many people did not participate in the tour?
某小学有男生378人，女生有346人．已知参加旅游的390人，没有参加旅游的有多少人？
<gadget id="calculator">346 - 390</gadget>
<output>-44</output>

<gadget id="calculator">378 + (-44)</gadget>
<output>334</output>

<result>334</result>