To write an integer for a situation, use positive integers for gains and negative integers for losses. For instance, earning money is modeled by a positive integer, while spending money is represented by a negative integer.
To write an integer to model a situation, you first need to understand what the situation is representing. For instance, if the situation describes a gain, such as depositing money into a bank account, you would use a positive integer.
Conversely, if the situation describes a loss, such as spending money or descending below sea level, you would use a negative integer.
For example, if a student earns $15 from doing chores, the situation can be modeled by the positive integer +15. If the same student spends $10 on a book, this can be modeled by the negative integer -10. The sign of the integer (+ or -) indicates whether the action adds or subtracts value in the given context.