How do we add negative whole numbers?
You might find a number line useful when answering questions involving negative numbers.
When you add a positive number, go up the number line.
When you subtract a positive number, go down the number line.
Example 1
\(6 - 3 = 6 + (\,- \,3) = 3\)
Example 2
\(4 - 5 = 4 + (\,-\,5) = - 1\)
Example 3
\( -\,2 + 5 = 3\)
Now try these questions and remember the number line!
Question
\(4 - 9\)
\(4 - 9 = 4 + (\,-\,9) = -\,5\)
Question
\(3 - 10\)
\(3 - 10 = 3 + (\,-\,10) = -\,7\)
Question
\(- 9 + 12\)
\(- 9 + 12 = 3\)