Because the question is incomplete, I can not fully answer. But, when you do add the other part of the question, I can help you with the rest! <3
Answer: 1 + -3 = -2
What to look for:
On the number line, it should be two decimal lines before one. But it depends on if you are counting by ones, or two's. If you are counting one by one, then this method works.
Have a great day! Please let me know if you need help with anything further on my end. <3