Sanskrit numbers (sankhya)

Hindi numbers are worn-down Sanskrit numbers, so the Sanskrit ones feel like old photographs of words you know: दो was द्वौ, तीन was त्रीणि, सात was सप्त, बारह was द्वादश. Number words are called संख्या (sankhya).

One point needs care. The numbers one to four are adjectives that change with the gender of the thing counted, and all number words take case endings. From five upward the same form is used for all genders.

One to four in the three genders (first case)

So: एकः बालकः (one boy), एका बालिका (one girl), एकं फलम् (one fruit); त्रयः बालकाः, तिस्रः बालिकाः, त्रीणि फलानि.

One to twenty

Tens and beyond

Making the numbers in between

Units come before tens, as in Hindi: 21 is एकविंशतिः ("one-twenty"), 25 is पञ्चविंशतिः, 32 is द्वात्रिंशत्, 45 is पञ्चचत्वारिंशत्, 99 is नवनवतिः. A number ending in nine is often said as "one less than" the next ten, with एकोन- or ऊन-: 19 is also एकोनविंशतिः, "twenty less one", which is where the Hindi उन्नीस comes from; 29 is एकोनत्रिंशत्.

Ordinals: first to tenth (masculine)

These ordinals are everywhere in Sanskrit books. The cases themselves are named by them (प्रथमा, द्वितीया, तृतीया..., in the feminine), and the chapters of the Gita are headed प्रथमोऽध्यायः, द्वितीयोऽध्यायः, "the first chapter, the second chapter".

Using numbers in sentences

• मम एकः भ्राता द्वे भगिन्यौ च सन्ति। I have one brother and two sisters.
• वृक्षे पञ्च खगाः सन्ति। There are five birds on the tree.
• अहं दशमकक्षायां पठामि। I study in the tenth class.
• कति वादनम्? सप्तवादनम्। What time is it? Seven o'clock.
• सप्ताहे सप्त दिनानि भवन्ति। There are seven days in a week.

Notes

• Nineteen is given as नवदश and as एकोनविंशतिः; both are correct.
• विंशतिः and the higher tens are feminine nouns and stay singular: विंशतिः बालकाः, twenty boys.
• The Devanagari digits ० १ २ ३ ४ ५ ६ ७ ८ ९ are used in Sanskrit books; verse numbers in the Gita are printed with them.

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