Method
How every number here is checked
A wrong character in an answer key costs a teacher's trust, so the numbers on this site come from one engine, and that engine is checked against a second, independent one for every number from 0 to 1,000,000.
The check
The site's engine builds a number by walking its digits and deciding about 零 as it goes, with the pinyin typed in its tone-marked form. The checker was written separately and works another way: it reads each block of four digits from a table with one hand-written template for every pattern of zeros and non-zeros, and it puts tone marks on numbered syllables (san1) with its own placement rule, built from Unicode code points. It also holds a hand-typed list of whole numbers, many taken from the examples printed in the two national standards, and refuses to run if its own derivation disagrees with them.
The decisions, and where they come from
Mandarin has more than one correct way to say some numbers. Each choice the site makes is listed here with its basis, and the answer keys accept the alternatives.
| Question | Printed | Also accepted | Basis |
|---|---|---|---|
| Zero | 零 for 0 and for gaps (一百零五) | none | GB/T 15835-2011 §5.2.5: 0 in a quantity is 零; 〇 is for labels such as years |
| Runs of zeros | one 零 (一千零五) | none | GB/T 16159-2012 §6.1.5.3 and GB/T 15835-2011 examples (三千零五十二, 两千零五十) |
| Ten | 十 opening a number (十五, 十万); 一十 inside one (一百一十) | none | Wikipedia "Chinese numerals", strict Putonghua (一百一十四); Yip and Rimmington (2004) |
| Two before 百, 千, 万 | 两 when it opens the number (两百, 两千, 两万); 二 inside (一千二百, 一万二千) | every mix of 两 and 二 in those places | GB/T 15835-2011 prints both 二百三十五 and 两千零五十; GB/T 16159-2012 prints 七万二千; Wikipedia gives three readings of 2,222 |
| Two elsewhere | 二 (二十, 十二, 二十二) | none | Wiktionary 兩 usage notes (三十兩 not Mandarin); Yip and Rimmington (2004) |
| Grouping | 万: 十万, 一百万 | none | GB/T 16159-2012 §6.1.5.3 examples |
| Short forms | not printed | 一百一 (110), 一千二 (1,200), 两万五 (25,000), last digit 二 | Wikipedia "Chinese numerals" (colloquial 一萬二) |
| Pinyin spacing | shí'èr, sānbǎi, yīwàn, shí wàn, èrshí wàn, líng as its own word | shíwàn joined | GB/T 16159-2012 §6.1.5.2 and §6.1.5.3 |
| Tones | citation tones: 一 is yī | yì, yí where a pupil marks the spoken change | GB/T 16159-2012 §6.5.2 |
| Apostrophe | ' before èr inside a word | none | GB/T 16159-2012 (Xī’ān, nǚ’ér); the plain apostrophe is used because Chinese fonts set ’ full width |
Example: 250 prints as 两百五十 liǎngbǎi wǔshí, and the key accepts 二百五十, 二百五, 两百五.
Scope
- Mandarin as standardised in mainland China: simplified characters and Hanyu Pinyin. Traditional characters (萬, 兩) are a later option for the worksheets.
- Cardinal numbers from 0 to 1,000,000. Dates, prices and phone numbers on the reference pages build on the same engine.
- Pronunciation notes follow the descriptions cited on the tones page; recordings use your device's own voice.
Questions from learners and teachers
What does the check actually compare?
For each number from 0 to 1,000,000: the characters the site prints, the pinyin it prints, and the full list of other answers its keys accept. A second program, written separately, produces all three from its own tables and the two must agree exactly, character by character. The pinyin is also checked letter by letter: only precomposed tone vowels, one tone mark per syllable on the vowel the pinyin rules name, each syllable the right reading of its character, and an apostrophe exactly where the spelling rules put one.
How do you know the checker would catch a real mistake?
By planting mistakes. Fourteen faults were put into a copy of the engine one at a time (a doubled 零, 两 before 十, 一十 at the start, a missing 零 after 万, a tone mark on the wrong vowel, a combining accent, a missing apostrophe, 〇 for zero, a Cyrillic letter that looks like a, and others). The checker failed on every one.
Why not print 二百 and 一百一 too?
A worksheet needs one answer per question for the pupil and every correct answer for the teacher. The printed form is the one we judge most common in standard Mandarin; the key lists the others beside it, so a pupil is not marked wrong for a form that is right.