Ten is "decem" in Latin. Decimal means, literally, base ten. It's a tautology either way. You can't even specify the base of the base since "base (10 in base 10

Ten is "decem" in Latin. Decimal means, literally, base ten. It's a tautology either way. You can't even specify the base of the base since "base (10 in base 10)" presents the same problem recursively. It's a non-problem though. I don't know about mathematicians, but when programmers say base N they mean N in decimal. EDIT: woops, replied to the wrong post.