In a hand in hand activity. The fourth grade donated 150 pieces of school supplies. The sixth grade donated 200 pieces of school supplies. The number of pieces donated by the fifth grade is (3/5) of the total number of the two grades. How many pieces of school supplies are donated in the fifth grade?
在一次拉手活动中．四年级共捐学习用品150件．六年级共捐学习用品200件．五年级捐的件数是两个年级总数的(3/5)．五年级捐学习用品多少件？
<gadget id="calculator">150 + 200</gadget>
<output>350</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">350 * (3/5)</gadget>
<output>210</output>

<result>210</result>