Use a number line to help represent the situation from the exercise. Recall how to describe changes on a number line using absolute values.
- 32
Practice makes perfect
We want to find the integer that represents the location of Rena's rowboat relative to shore. We can use a number line to help visualize the given situation. From the exercise, we know that the rowboat drifts 23 feet from shore. Then it drifts 9 feet further out. Let's list the steps we can follow to create a number line for this situation.
First, we start at 0.
Then, we move 23 units to the left, which represents the rowboat's location after the first time it drifts away.
Finally, we move 9 units to the left. We do this to represent the rowboat continuing to drift.
Now, we can mark these steps on a number line.
As we can see from the graph, the sum of - 23 and - 9 is located 9 units to the left of - 23. We can add the two integers to find the rowboat's location. Let's take a look at the expression from the exercise.
-23+(-9)
Notice that we are adding two integers with the samesigns, both negative. Because of this, we will add the absolute values of the integers. Let's do it!
Keep in mind that we moved to the left of 0 on the number line two times. Because of this, the result is negative and we can say that Rena's rowboat is 32 feet from shore. The integer that represents this is - 32.
