Indian l can you simplify this?? l Olympiad Math Simplification l Calculator not Allowed

[@kpi6438]

Strange! I always had a very high opinion of Indian mathematicians and programmers. And here is a primitive computational problem.

[@rabotaakk-nw9nm]

3:35-6:30 729²=
=(700+(30-1))²=
=700²+(30-1)²+2(700)(30-1)=
=7²(100²)+30²+1²-2(30)1+2(21000-700)=
=49(10⁴)+900+1-60+2(20300)=
=490000+841+40600=
=531441 😁