Arrange 45 □ in 8 rows, if there are 6 □ in each row, how many □ are left?
把45个□摆成8排，如果每排要摆6个□，还差多少个□．
<gadget id="calculator">6 * 8</gadget>
<output>48</output>

<gadget id="calculator">48 - 45</gadget>
<output>3</output>

<result>3</result>