Above ten come ग्यारह (11), बारह (12), पंद्रह (15), अठारह (18) and बीस (20).

These twenty carry most of daily life — prices, times, quantities, ages. Learn them properly before touching anything higher, because the numbers above twenty are irregular and there is little point struggling with सत्तावन before एक to बीस are automatic.

The last three are अस्सी (80), नब्बे (90) and सौ (100).

The decades are the second thing to learn, because they let you approximate. Knowing that something costs सत्तर something is usually enough even if the exact figure escapes you, and Indians will often round to the decade in speech anyway.

Between the decades, the numbers must simply be memorised. Some are subtractive — उनतीस is 29, literally one-less-than-thirty, and उनतालीस is 39 — but the pattern is inconsistent enough that it is not a reliable shortcut.

Indian grouping goes हज़ार, लाख, करोड़ rather than thousand, million, billion, and the comma placement follows it: one lakh is written 1,00,000 and one crore is 1,00,00,000. Salaries, property prices, film earnings and population figures all use this system exclusively.

Conversions worth memorising: one lakh is a hundred thousand, ten lakh is a million, one crore is ten million, and a hundred crore is a billion.

Ordinals are regular enough: पहला (first), दूसरा (second), तीसरा (third), then चौथा and पाँचवाँ.

Hindi has dedicated single words for 1.5 and 2.5, which English lacks, and they are used constantly for time and weight — डेढ़ घंटा, ढाई किलो. The prefixes सवा, साढ़े and पौने cover quarters: सवा तीन is 3:15, साढ़े तीन is 3:30 and पौने चार is 3:45. Note that पौने attaches to the following hour.

Hindi also has its own digit symbols, still seen on old signage, government documents and some price boards.

• १ २ ३ ४ ५ — one to five
• ६ ७ ८ ९ ० — six to nine and zero
• Arabic numerals are now standard in most contexts, but recognising these is occasionally necessary.

Learners rarely need to write these, but a bus number or a page reference in Devanagari digits can genuinely stop you, so five minutes spent recognising them is worthwhile.

पाँच is nasalised and ends in ch, not a hard n. छह opens with aspirated chh. आठ ends in a retroflex ṭh. हज़ार and डेढ़ both contain sounds English lacks — the nukta z and the aspirated flap ढ़. Practise the numbers you use most, since a misheard price is one of the more consequential errors a learner can make.

• Trying to derive numbers logically. इक्कीस cannot be built from एक and बीस.
• Converting lakh to million incorrectly. One lakh is a hundred thousand.
• Reading 1,00,000 as one hundred thousand written wrongly. It is one lakh.
• Saying पौने तीन when you mean 3:45. It attaches to the hour ahead.
• Learning all hundred numbers before mastering one to twenty.

1. Count one to twenty aloud without pausing.
2. Say all eight decades from thirty to a hundred.
3. Convert three salaries into lakh per annum.
4. Say six clock times using सवा, साढ़े and पौने.
5. Read five prices written in Devanagari numerals.