Step by step
The question
Question: It is −11°F.
It rises 15 degrees.
What is the temperature now?
1 Write it as a sum
We start at −11.
Rises means up: add 15.
−11 + 15
Below zero is negative.
−11°F: below zero
rises 15 → + 15
2 Work it out
Start at −11.
Go up 15.
We pass 0.
Careful!
We start at −11, not at 11.
Keep the minus sign.
Careful: not 11 + 15 = 26 ✗
We land on 4°F.
= 4°F
So the answer is 4°F: 4 degrees above zero.
3 Check
Let's check: go back.
4 minus 15 is −11, where we started.
So the answer is right!
4 − 15 = −11
Let's look back.
First: write it as a sum.
Then: work it out.
Last: check.
Answer
= 4°F