7.NS.1c

7.NS.1c. Understand subtraction of rational numbers as adding the additive inverse, //p - q = p + (-q)//. Show that the distance between two rational numbers on the number line is the absolute value of their difference, and apply this principle in real-world contexts.

- This activity comes from a California group called the PRIME project. It is a "story" about adding and subtracting hot and cold cubes (positives and negatives) to adjust the temperature of the soup.