Using (1/2), (3/10), 4.5, 7.5 as a ratio, what is the product of the two outer terms
用(1/2)、(3/10)、4.5、7.5四个数组成比例，其两个外项的积是多少
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 4.5</gadget>
<output>2.25</output>

<result>2.25</result>