A red rope is 7 cm long, and a blue rope is 55 mm long. If these two ropes are connected together and 2 cm is used at the joint, what is the length of the resulting rope?
一根红绳长7厘米，一根蓝绳长55毫米，若把这两根绳子接在一起，接头处用去2厘米，则接成的这根绳长多少？
<gadget id="calculator">55 - 2</gadget>
<output>53</output>

<gadget id="calculator">7 + 53</gadget>
<output>60</output>

<result>60</result>