Calculation: 3*150=how much.
计算：3*150=多少．
<gadget id="calculator">100 * 3</gadget>
<output>300</output>

<gadget id="calculator">50 * 3</gadget>
<output>150</output>

<gadget id="calculator">300 + 150</gadget>
<output>450</output>

<result>450</result>