Displaying Slider Values: Thermometer Activity

I am creating an activity where students select the recommended cooking temperatures for different types of meat. I thought that a slider would be ideal, because it looks like a thermometer and would be the natural way for students to pick a temperature. However, I am not able to find a way to make the number values (degrees F) show up when the thumb slides back and forth.  

I read through the "Working with Sliders" page, which says to add a Variable Reference to the slider, but that hasn't worked for me. For now, I have just put in a picture of a thermometer, not to scale, and have four arrows pointing to temperatures. The student selects the correct temperature for that meat (a Pick One freeform question, see screenshot). However, if you have any insights that could help me to get the slider working, that would be much appreciated!