Lesson 1: The Number Line
Why is 3 + (−5) equal to −2?
(1 point)
Group of answer choices
Because it is 5 units to the left of 0 on a horizontal number line
Because it is 5 units to the right of 3 on a horizontal number line
Because it is 5 units to the left of 3 on a horizontal number line
Because it is 5 units to the right of 0 on a horizontal number line
Because it is 5 units to the left of 3 on a horizontal number line.
The correct answer is: Because it is 5 units to the left of 3 on a horizontal number line.
In mathematics, adding a negative number can be thought of as moving to the left on a number line. In this case, adding -5 to 3 means moving 5 units to the left of 3, which gives us -2.
To understand why 3 + (-5) is equal to -2, we can use a number line as a visual representation.
1. Start by locating the number 3 on a horizontal number line.
2. The operation "+" represents addition, so we want to move to the right by 5 units.
3. However, in this case, we have a negative number (-5) that we need to add.
4. When adding a negative number, we actually move to the left by that number of units.
5. So, starting from 3, we move 5 units to the left on the number line.
6. This brings us to the number -2, which means that 3 + (-5) is equal to -2.
In summary, the correct explanation is "Because it is 5 units to the left of 3 on a horizontal number line."