Step by step
The question
Question: what is the difference between −2°F and 9°F?
difference between −2°F and 9°F
The difference is how far apart the two numbers are.
It is never negative.
difference = how far apart
1 Mark both numbers
On the number line: −2 and 9.
We go from the smaller one, −2, up to the bigger one, 9.
2 Bigger minus smaller
The bigger one minus the smaller one: 9 minus −2.
= 9 − (−2)
Taking away a negative is the same as adding.
Minus minus 2 is plus 2.
= 9 + 2
Careful!
Do not drop the minus sign of −2.
−2 is below zero, so it is further away.
Careful: not 9 − 2 = 7 ✗
9 plus 2 is 11°F.
= 11°F
So the difference is 11 degrees.
3 Check
Let's check in two parts.
From −2 up to 0 is 2.
From 0 up to 9 is 9.
2 plus 9 is 11.
So the answer is right!
−2 to 0: 2, 0 to 9: 9, 2 + 9 = 11
Let's look back.
First: mark both numbers.
Then: bigger minus smaller.
Last: check.
Answer
= 11°F