Use 28 matchsticks to place triangles and squares (one matchstick on each side), 8 in total, how many squares and triangles are placed?
用28根火柴棒摆三角形和正方形(每边一根火柴棒)，共摆了8个，正方形和三角形各摆几个？
<gadget id="calculator">4 * 8</gadget>
<output>32</output>

<gadget id="calculator">32 - 28</gadget>
<output>4</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">8 - 4</gadget>
<output>4</output>

<result>4</result>