A Hope Primary School received 800 books donated from other places, and plans to distribute the books to the second to sixth grades, with 10 more books for each senior grade. According to this plan, how many books are there for the fifth grade?
一个希望小学收到外地捐书800本，计划把书分给二年级到六年级，每高一年级就多分10本．按这个计划，分给五年级的图书有多少本．
<gadget id="calculator">800 - 10 - 20 - 30 - 40</gadget>
<output>700</output>

<gadget id="calculator">1 + 1 + 1 + 1 + 1</gadget>
<output>5</output>

<gadget id="calculator">700 / 5</gadget>
<output>140</output>

<gadget id="calculator">140 + 30</gadget>
<output>170</output>

<result>170</result>