Teacher Wang went to the stationery store to buy the same exercise books. With the money he brought, if he bought 9 exercise books. It will be 2 yuan and 50 cents more; if you buy 10 exercise books, you will lose 1 yuan. How much money did Mr. Wang bring in total?
王老师到文具店去买同样的练习本，他带的钱，如果买9本练习本．就多2元5角；如果买10本练习本，就少了1元钱．王老师一共带了多少钱？
<gadget id="calculator">2.5 + 1</gadget>
<output>3.5</output>

<gadget id="calculator">10 - 9</gadget>
<output>1</output>

<gadget id="calculator">3.5 / 1</gadget>
<output>3.5</output>

<gadget id="calculator">3.5 * 10</gadget>
<output>35</output>

<gadget id="calculator">35 - 1</gadget>
<output>34</output>

<result>34</result>