theory that a few numbers come from the same letter as they are described with. notables include 1, 2, 3, 4, 5, 6. see also evolution of numbers: Georges Ifrah, The Universal History of Numbers pp 368-396.
੧ੲ੧ੲ
੧ ਇੱਕ
੨ਦ੨ਦ
੨ ਦੋ
੩ਤ੩ਤ
੩ ਤਿੰਨ
੪ਚ੪ਚ
੪ ਚਾਰ
੫ਪ੫ਪ
੫ ਪੰਜ
੬ਛ੬ਛ
੬ ਛੇ
੭ਸ੭ਸ
੭ ਸੱਤ
੮ਅ੮ਅ
੮ ਅੱਠ
੯ਨ੯ਨ
੯ ਨੌਂ