Curious 123456789 x 8 + 9 = 987654321
50662
Why does this pattern occur: $123456789 \times 8 + 9 = 987654321$
95702
Remarkable/unexpected rational numbers
144025
Number of Solutions in this Number Puzzle
87968
A strange puzzle having two possible solutions
75723
Odd Binomial Coefficients?
5106
What does E mean in 9.0122222900391E-5?
103545
Prove "casting out nines" of an integer is equivalent to that integer modulo 9
22397
Is 0.9999... equal to -1?
115145
Show that $n-m$ is a multiple of 9 when $n$ and $m$ have same digits
123140
Using 9-test or 11-test to find digit x in 52817*3212146 = 169655x15282
87626
Why are all $n$, s.t. the sum of digits of $n$ and $n^2$ coincide, $\equiv 0,1 \bmod 9$
150281
Am I on the right track to figure out this combinatorics problem?
63549
Find all integer solutions to $7595x + 1023y=124$
27249
How many digits does $2^{1000}$ contain?
9343
Why does $\frac{1 }{ 99989999}$ generate the Fibonacci sequence?
9105
Finding the last two digits $123^{562}$
53325
Are there integer solutions to $9^x - 8^y = 1$?