Answer: -3 + 4 = 1
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Step-by-step explanation:
We start at the bottom layer.
That arrow on the bottom layer goes from 0 to -3. In short, it represents the number -3.
The upper arrow moves from -3 to +1 or simply 1. This is a distance of 4 spaces. So we add on 4.
Overall, this diagram represents -3+4 = 1