The teachers and students of Hongxing Primary School donated money to the children in the disaster area. The students donated 420 yuan, which was 90 yuan more than the amount donated by the teachers. How much did the teachers and students donate in total?
红星小学师生向灾区小朋友捐款，学生捐款420元，比老师捐款数多90元，师生共捐款多少元？
<gadget id="calculator">420 - 90</gadget>
<output>330</output>

<gadget id="calculator">330 + 420</gadget>
<output>750</output>

<result>750</result>