Yes, https://www.mathsisfun.com/numbers/bases.html has a bunch more examples to show why the base of the number system is always represented by 10, because 10 is a short hand we use for d1*b^1 + d2*b^0 where d is a digit between 0 and base-1, and b is the base. b^0 is always one and represents the first digit at the first position. b^1 is the base, so 1*b^1 = the base. And since 10 is 1*b^1 + 0*b^0 it represents the base in any number base system.
We assume a 1 in the 10’s place and a 0 in the 1’s represents 1,2,3,…,10 of something instead of 0,1,2,3,10 of something because from our perspective we learned numbers in base 10 with 9 digits, but the alien learned 10 means 4 of something in base 4.
Yes, https://www.mathsisfun.com/numbers/bases.html has a bunch more examples to show why the base of the number system is always represented by 10, because 10 is a short hand we use for d1*b^1 + d2*b^0 where d is a digit between 0 and base-1, and b is the base. b^0 is always one and represents the first digit at the first position. b^1 is the base, so 1*b^1 = the base. And since 10 is 1*b^1 + 0*b^0 it represents the base in any number base system.
Another way to show the same thing with counting:
Base 10: 0, 1, 2, …, 8, 9, 10, 11, 12…
Base 4: 0, 1, 2, 3, 10, 11, 12, 13, 20, …
Any base: d1*b^0 , d2*b^0 , …, d(b-1)*b^0 , d1*b^1 + d1*b^0 , d1*b^1 + d2*b^0 , …
We assume a 1 in the 10’s place and a 0 in the 1’s represents 1,2,3,…,10 of something instead of 0,1,2,3,10 of something because from our perspective we learned numbers in base 10 with 9 digits, but the alien learned 10 means 4 of something in base 4.