Calculate $121^{199} \mod 300$
360
Modular exponentiation by hand ($a^b\bmod c$)
141183
How to determine highest power of $2$ in $3^{1024}-1$?
99328
Value of $\sin (2^\circ)\cdot \sin (4^\circ)\cdot \sin (6^\circ)\cdots \sin (90^\circ) $
42391
Calculate $\tan9^{\circ}-\tan27^{\circ}-\tan63^{\circ}+\tan81^{\circ}$
75489
Solve $x^2$ $mod$ $23 = 7^2$
90739
Linear diophantine equation $100x - 23y = -19$
109490
Modular arithmetic problem (mod $13$)
140728
Give me some hints in calculation this limit.
49626
Find the last two digits of $33^{100}$
32183
A "fast" way for  computing $ \prod \limits_{i=1}^{45}(1+\tan i^\circ) $?
97666
Prove $133\mid \left(11^{n+2}+12^{2n+1}\right)$
4972
Mod of numbers with large exponents [modular order reduction]
119433
How to find modulo of large numbers like $9801\! \pmod {\!32}$
102444
What is $26^{32}\bmod 12$?
84788
Find limit of $\lim_{x\to 0}\frac{\sin^{200}(x)}{x^{199}\sin(4x)}$, if it exists
55984
How can I find the answer to $\varphi(2^{400} + 2)$?
139776
Divisibility tests and remainder mod $9,11,99,101,999,1001\,$ (casting out nines and elevens)