The extra gap at 100 is caused by the way Word aligns multi‑digit numbers in the list, not by normal paragraph spacing. Adjusting the list’s number formatting/indentation fixes it.
Use a multilevel list definition so the indent is controlled consistently:
- Click in the first item of the numbered list.
- On the Home tab, in the Paragraph group, open the Multilevel List menu and choose Define New Multilevel List.
- In the dialog, select the level used for this list (usually Level 1).
- Adjust the Number position and Text indent so that the text lines up correctly for both single‑ and triple‑digit numbers (for example, reduce the Text indent value so the gap after 100 is smaller).
- Apply the changes.
This dialog gives control over indentation and alignment so that when the list reaches 100, Word does not insert a large fixed gap before the text.
If the Tab key no longer changes list levels while adjusting the list, ensure the option “Set left and first-indent with tabs and backspaces” is enabled (File > Options > Proofing > AutoCorrect Options > AutoFormat As You Type).
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