Visualise 2.874 on the number line, using successive magnification.

We know that 2.874 lies between 2 and 3. So, let us decide the part of the number line between 2 and 3 into 10 equal parts and look at the portion between 2.8 and 2.9 through a magnifying glass.

Now, 2.874 lies between 2.8 and 2.9. Now, we imagine to divide this again into 10 equal parts. The first mark will represent 2.81, then next 2.82 and so on.

Again, 2.875 lies 2.87 and 2.88. Let us imagine and divide into 10 equal parts.

This is representation of numbers on the number line through a magnification glass.

Thus, we can visualize that 2.871 is the first mark 2.874 is the 4^th mark in these subdivisions.