Five roses cost 8 yuan, and four carnations cost 7 yuan. Which flower do you think is the cheapest? How much cheaper?
玫瑰花5枝8元钱，康乃馨4枝7元钱，你认为哪种花便宜？便宜多少钱？
<gadget id="calculator">7 / 4</gadget>
<output>7/4 = around 1.75</output>

<gadget id="calculator">8 / 5</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">(7/4) - (8/5)</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>