Scales of notation

A number written in base $b$ has digits in positions representing powers of $b$, starting with $b^0$ on the right. Its value is the sum of each digit times its place value. For example, $234_b=2\times b^2+3\times b^1+4\times b^0$. Every digit must be smaller than $b$. Base ten is the usual decimal system; other bases work the same way with their own powers.