Daria wants to go to a concert by her favorite band. She wants to buy tickets for her and for three of her friends. One ticket cost is $90. How much money does Daria need to earn if she currently has only $189?
Daria wants to buy tickets for four persons, so the cost will be 4 tickets * $90/ticket = $
<gadget id="calculator">4*90</gadget>
<output>360</output>
360.
Daria currently has $189, so she needs $360 - $189 = $
<gadget id="calculator">360-189</gadget>
<output>171</output>
171 more.

<result>171</result>