The number line you described illustrates the division problem 12 divided by 3 = 4.
Here's the reasoning: The number line jumps in increments of 3 (from 0 to 3, then 3 to 6, 6 to 9, and finally 9 to 12) until reaching 12. Each jump represents one part of a total that is being divided. Since there are 4 jumps of 3 to reach 12, it shows that 12 divided by 3 equals 4.
The other division problems (9 divided by 3 = 3 and 12 divided by 2 = 6) do not correspond directly to the increments illustrated on the number line.