Bring a large thermometer to class to use as a tool for demonstrations. If you do not have access to a thermometer that is large enough for the entire class to see, you can draw one on white construction paper, color in a red line to indicate the temperature and cut it out. Make one thermometer that represents a low temperature and another to represent a higher heat level. Ask students to identify the parts of the thermometer. Explain that temperature can be measured digitally or using the poisonous substance mercury. Ask them what would happen with the line of mercury on a hot day and a cold day, and show them examples using the two thermometers you have drawn.
Bring first-graders to a school kitchen or lab. Set a pot of water boiling. Do not let children touch the pot or approach the stove. When the water has reached a full boil, insert a cooking thermometer and demonstrate to children that water boils at 212 degrees Fahrenheit. Next, extract a bag of ice chips from the freezer. Allow the food thermometer to return to room temperature, and place the tip amongst the pieces of ice. Explain that when measured in Fahrenheit, water freezes at 32 degrees instead of 0. Allow children to witness the change in the thermometer as you transfer it between substances of different temperatures.
Chart the weather while teaching children about Fahrenheit temperature measurements. Install an outdoor weather thermometer outside of your classroom. You can place this on an outer wall if you are conducting this experiment during temperate weather. If not, place it where it is visible from your classroom window. Each day for one week, assign two students to determine and record the outside temperature in Fahrenheit. Keep a list of the data, and at the end of the week, help first-graders make a graph illustrating the fluctuations in temperature they have recorded.
Bring in a digital thermometer used to take the temperatures of patients. Sanitize the tip and ask for a student volunteer. Now that the class has learned average weather temperatures and water’s freezing and boiling points, they should understand the basics of Fahrenheit measurements. Ask them to guess what average, healthy body temperature is when measured in Fahrenheit and take the temperature of the volunteer. Explain to the first-graders that healthy human body temperature is 98.6 and anything higher indicates fever and illness that must be treated to avoid brain damage.