Answer:
20
Step-by-step explanation:
To find the value at the blue dot, you must identify the scale of the markings of the number line.
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what is the scale
12 is 2 marks to the right of 8, so we know 2 marks has a value of 12-8 = 4.
using the scale
That means the second mark to the right of 12 will be 12+4 = 16.
The second mark to the right of that is 16+4 = 20, which is where the blue dot is.
The value at the blue dot is 20.
