anesthetic
I dont think any number starts with letter A.
billion
number
quite
Sesame Street
Hydrogen is a chemical element with the atomic number 1.
twelve
Eight
Annual is a period of time. It begins with the letter a.
A letter that starts with U is an urgent letter.
The letter at the end of the serial number is treated like an extra digit. For example if the letter starts as A, when the number portion reaches 99999999 the letter clicks up to "B", the number is reset, and the process starts all over again. The leading letter on all bills indicates the Federal Reserve District that distributed the bill. On higher-denomination notes there's a second letter before the serial number that again is treated like a digit.
Bear starts with the letter B