How it is 10 base 10 equals A base 11?

Answer 1

Base 10 is based on groupings of 10, and the digits are called 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. Base 11 is based on groupings of 11, and the digits are called 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and A. A is used instead of 10 to avoid confusion, because it is a single digit, not two digits that actually have the base 10 value of 11.

Notice in 10 base 10, you are using 2 digits, a 1 in the tens place and a 0 in the ones place. In base 11, you only need 1 digits, an A, which has the same effective value.