The fruit store has to ship 90 boxes of oranges, and they have shipped 7 times, 9 boxes each time, how many boxes are left unshipped?
水果店要运90箱桔子，运了7次，每次运9箱，还有多少箱没有运？
<gadget id="calculator">9 * 7</gadget>
<output>63</output>

<gadget id="calculator">90 - 63</gadget>
<output>27</output>

<result>27</result>