An inclusive-method table has a gap between one class's upper limit and the next class's lower limit; that gap is closed by adjusting every limit by half the gap.

Step 1 — find the gap. Between the upper limit of one class (9) and the lower limit of the next class (10), the gap is $10 - 9 = 1$.

Step 2 — take half the gap. $\dfrac{1}{2} = 0.5$.

Step 3 — adjust every class. Subtract 0.5 from every lower limit and add 0.5 to every upper limit; the frequencies stay exactly as given, only the boundaries change.

Verification (dual-check): the new classes now share common boundaries with no gap and no overlap (9.5 ends class 1 and starts class 2, 19.5 ends class 2 and starts class 3, and so on) and the total frequency is unchanged at $4+10+16+8+2 = 40$, matching the given 40 students — confirming the conversion only changed the boundaries, not the data. This exclusive-method table is now ready for a histogram to be drawn on it.

Alternative check: instead of subtracting/adding 0.5 to limits, some textbooks state the boundary directly as the midpoint of the upper limit of one class and the lower limit of the next — $\dfrac{9+10}{2} = 9.5$ — which gives the identical boundary of 9.5, confirming the method above.

A common error is adding the full gap (1) instead of half the gap (0.5), which wrongly changes the class width; another is adjusting only the upper limits and forgetting to also adjust the lower limits, which breaks the continuity between classes.