This Formative includes a video discussing the difference between temperature and thermal energy and then gives the students some practice questions.
One last point to ponder:
Remember, the temperature of the hot water was 42 degrees. The temperature of the cold water was 12 degrees. The halfway point between those two temperatures is 27 degrees. But the temperature of the mixed water is 24 degrees, which is not halfway in between, but a little closer to the cold water temperature than to the hot water temperature. Why do you think the mixed water temperature ended up a little bit below the halfway temperature?

Find the total thermal energy of the cold water.
Now find the temperature of the cold water.

If we mix the hot and cold water molecules, the hot water molecules will __________ thermal/kinetic energy.

What is the total thermal energy of the mixed water?
What is the temperature of the mixed water?
The cold water molecules will __________ thermal/kinetic energy.