Step by step
The question
Question: It is 3°C.
It gets 8 degrees colder.
What is the temperature now?
1 Write it as a sum
We start at 3.
Colder means down: take away 8.
3 − 8
Below zero is negative.
3°C
colder 8 → − 8
2 Work it out
Start at 3.
Go down 8.
We pass 0.
Careful!
We start at 3, not at 3.
Keep the minus sign.
Careful: not 3 − 8 = -5 ✗
We land on −5°C.
= −5°C
So the answer is −5°C: 5 degrees below zero.
3 Check
Let's check: go back.
−5 plus 8 is 3, where we started.
So the answer is right!
−5 + 8 = 3
Let's look back.
First: write it as a sum.
Then: work it out.
Last: check.
Answer
= −5°C