4. Numbers

4.1 Spell out numbers up to one hundred except when expressing dimensions, in statistical contexts, or in tables. Use Arabic for 101+ except when beginning a sentence. Spell out hundreds and thousands.

fifteen stools, sixty-one parrots, 156 canisters, one thousand lives, 34 × 67 cm

4.2 No commas are required for four-digit numbers (i.e. up to 9999), but should be used for every three digits thereafter (i.e. 10,000 and higher).

2400, 67,000, 207,000, 2,500,000

4.3 Number ranges follow the "spoken number" convention.

1–45
56–76
100–102
102–6
287–88
287–91
1000–1004
1015–56
1785–893