Answer:
250
Explanation:
You can think of this in different ways. Here are two ways.
1) The distance between any two points on the number line is the absolute value of the difference of the coordinates. Since you will take the absolute value of the difference, it makes no different in which order you do the subtraction.
For points on the number line with coordinates a and b,
distance = |a - b| = |b - a|
Here the coordinates are -130 and 120.
distance = |-130 - 120| = |-250| = 250
distance = |120 - (-130)| = |120 + 130| = |250| = 250
As you can see, the distance comes out the same no matter the order of the subtraction.
distance = 250
2) Just think of what the problem means and do a little calculation.
120 is a positive number, so it is located 120 units to the right of zero.
-130 is a negative number, so it is located 130 units to the left of zero.
To find the distance between the two numbers, think of starting at -130. You need to go 130 units right to reach zero. Then from zero you need to move another 120 units right to reach 120. The total distance is 130 + 120 which equals 250.
distance = 250